change data type of bgemm alpha and beta from bfloat16 to fp32 and add makefiles changes for bgemm interface

CONTRIBUTORS.md

@@ -251,6 +251,7 @@ In chronological order:
 * Ye Tao <ye.tao@arm.com>
   * [2025-02-03] Optimize SBGEMM kernel on NEOVERSEV1
   * [2025-02-27] Add sbgemv_n_neon kernel
+  * [2025-05-17] Impl prototype of BGEMM inferface
 
 * Abhishek Kumar <https://github.com/abhishek-iitmadras>
-  * [2025-04-22] Optimise dot kernel for NEOVERSE V1
+  * [2025-04-22] Optimise dot kernel for NEOVERSE V1 

Makefile.system

@@ -1544,6 +1544,9 @@ ifeq ($(USE_TLS), 1)
 CCOMMON_OPT += -DUSE_TLS
 endif
 
+ifeq ($(BUILD_BFLOAT16_ONLY), 1)
+CCOMMON_OPT += -DBUILD_BFLOAT16_ONLY
+endif
 ifeq ($(BUILD_BFLOAT16), 1)
 CCOMMON_OPT += -DBUILD_BFLOAT16
 endif
@@ -1888,6 +1891,7 @@ export FUNCTION_PROFILE
 export TARGET_CORE
 export NO_AVX512
 export NO_AVX2
+export BUILD_BFLOAT16_ONLY
 export BUILD_BFLOAT16
 export NO_LSX
 export NO_LASX
@@ -1912,7 +1916,7 @@ export ZGEMM3M_UNROLL_M
 export ZGEMM3M_UNROLL_N
 export XGEMM3M_UNROLL_M
 export XGEMM3M_UNROLL_N
-
+# Todo: add bgemm unroll factors
 
 ifdef USE_CUDA
 export CUDADIR

Makefile.tail

@@ -11,7 +11,7 @@ COMMONOBJS_P = $(COMMONOBJS:.$(SUFFIX)=.$(PSUFFIX))
 
 HPLOBJS_P   = $(HPLOBJS:.$(SUFFIX)=.$(PSUFFIX))
 
-BLASOBJS    = $(SBEXTOBJS) $(SBBLASOBJS)  $(SBLASOBJS)   $(DBLASOBJS)   $(CBLASOBJS)   $(ZBLASOBJS) $(CBAUXOBJS)
+BLASOBJS    = $(SBEXTOBJS) $(BBLASOBJS) $(SBBLASOBJS)  $(SBLASOBJS)   $(DBLASOBJS)   $(CBLASOBJS)   $(ZBLASOBJS) $(CBAUXOBJS)
 BLASOBJS_P  = $(SBEXTOBJS_P) $(SBBLASOBJS_P) $(SBLASOBJS_P) $(DBLASOBJS_P) $(CBLASOBJS_P) $(ZBLASOBJS_P) $(CBAUXOBJS_P)
 
 ifdef EXPRECISION
@@ -24,6 +24,7 @@ BLASOBJS   += $(QBLASOBJS)   $(XBLASOBJS)
 BLASOBJS_P += $(QBLASOBJS_P) $(XBLASOBJS_P)
 endif
 
+$(BBLASOBJS) : override CFLAGS += -DBFLOAT16_ONLY -UDOUBLE  -UCOMPLEX -UBFLOAT16 -USMALL_MATRIX_OPT
 $(SBBLASOBJS) $(SBBLASOBJS_P) : override CFLAGS += -DBFLOAT16 -UDOUBLE  -UCOMPLEX
 $(SBLASOBJS) $(SBLASOBJS_P) : override CFLAGS += -UDOUBLE  -UCOMPLEX
 $(DBLASOBJS) $(DBLASOBJS_P) : override CFLAGS += -DDOUBLE  -UCOMPLEX
@@ -42,6 +43,7 @@ $(ZBLASOBJS_P) : override CFLAGS += -DPROFILE $(COMMON_PROF)
 $(XBLASOBJS_P) : override CFLAGS += -DPROFILE $(COMMON_PROF)
 $(SBEXTOBJS_P) : override CFLAGS += -DPROFILE $(COMMON_PROF)
 
+
 libs    :: $(BLASOBJS) $(COMMONOBJS)
 	$(AR) $(ARFLAGS) -ru $(TOPDIR)/$(LIBNAME) $^
 

cblas.h

@@ -475,7 +475,7 @@ void cblas_sbgemm_batch(OPENBLAS_CONST enum CBLAS_ORDER Order, OPENBLAS_CONST en
 		       OPENBLAS_CONST float * alpha_array, OPENBLAS_CONST bfloat16 ** A_array, OPENBLAS_CONST blasint * lda_array, OPENBLAS_CONST bfloat16 ** B_array, OPENBLAS_CONST blasint * ldb_array, OPENBLAS_CONST float * beta_array, float ** C_array, OPENBLAS_CONST blasint * ldc_array, OPENBLAS_CONST blasint group_count, OPENBLAS_CONST blasint * group_size);
 
 void   cblas_bgemm(OPENBLAS_CONST enum CBLAS_ORDER Order, OPENBLAS_CONST enum CBLAS_TRANSPOSE TransA, OPENBLAS_CONST enum CBLAS_TRANSPOSE TransB, OPENBLAS_CONST blasint M, OPENBLAS_CONST blasint N, OPENBLAS_CONST blasint K,
-		    OPENBLAS_CONST bfloat16 alpha, OPENBLAS_CONST bfloat16 *A, OPENBLAS_CONST blasint lda, OPENBLAS_CONST bfloat16 *B, OPENBLAS_CONST blasint ldb, OPENBLAS_CONST bfloat16 beta, bfloat16 *C, OPENBLAS_CONST blasint ldc);
+		    OPENBLAS_CONST float alpha, OPENBLAS_CONST bfloat16 *A, OPENBLAS_CONST blasint lda, OPENBLAS_CONST bfloat16 *B, OPENBLAS_CONST blasint ldb, OPENBLAS_CONST float beta, bfloat16 *C, OPENBLAS_CONST blasint ldc);
 
 #ifdef __cplusplus
 }

common_interface.h

@@ -481,8 +481,8 @@ void BLASFUNC(xhbmv)(char *, blasint *, blasint *, xdouble *, xdouble *, blasint
 		    xdouble *, blasint *, xdouble *, xdouble *, blasint *);
 
 /* Level 3 routines */
-void BLASFUNC(bgemm)(char *, char *, blasint *, blasint *, blasint *, bfloat16 *,
-	   bfloat16 *, blasint *, bfloat16 *, blasint *, bfloat16 *, bfloat16 *, blasint *);
+void BLASFUNC(bgemm)(char *, char *, blasint *, blasint *, blasint *, float *,
+	   bfloat16 *, blasint *, bfloat16 *, blasint *, float *, bfloat16 *, blasint *);
 void BLASFUNC(sbgemm)(char *, char *, blasint *, blasint *, blasint *, float *,
 	   bfloat16 *, blasint *, bfloat16 *, blasint *, float *, float *, blasint *);
 void BLASFUNC(sgemm)(char *, char *, blasint *, blasint *, blasint *, float *,

common_level3.h

@@ -54,7 +54,7 @@ void sgemm_direct(BLASLONG M, BLASLONG N, BLASLONG K,
 
 int sgemm_direct_performant(BLASLONG M, BLASLONG N, BLASLONG K);
 
-int bgemm_beta(BLASLONG, BLASLONG, BLASLONG, bfloat16,
+int bgemm_beta(BLASLONG, BLASLONG, BLASLONG, float,
 	       bfloat16 *, BLASLONG, bfloat16 *, BLASLONG, bfloat16 *, BLASLONG);
 int sbgemm_beta(BLASLONG, BLASLONG, BLASLONG, float,
 	       bfloat16 *, BLASLONG, bfloat16 *, BLASLONG, float *, BLASLONG);
@@ -513,7 +513,7 @@ int xher2k_kernel_LN(BLASLONG m, BLASLONG n, BLASLONG k, xdouble alpha_r, xdoubl
 int xher2k_kernel_LC(BLASLONG m, BLASLONG n, BLASLONG k, xdouble alpha_r, xdouble alpha_i, xdouble *a, xdouble *b, xdouble *c, BLASLONG ldc, BLASLONG offset, int flag);
 
 // add bgemm kernel
-int bgemm_kernel(BLASLONG, BLASLONG, BLASLONG, bfloat16,  bfloat16 *, bfloat16 *, bfloat16 *, BLASLONG);
+int bgemm_kernel(BLASLONG, BLASLONG, BLASLONG, float,  bfloat16 *, bfloat16 *, bfloat16 *, BLASLONG);
 int sbgemm_kernel(BLASLONG, BLASLONG, BLASLONG, float,  bfloat16 *, bfloat16 *, float *, BLASLONG);
 int sgemm_kernel(BLASLONG, BLASLONG, BLASLONG, float,  float  *, float  *, float  *, BLASLONG);
 int dgemm_kernel(BLASLONG, BLASLONG, BLASLONG, double, double *, double *, double *, BLASLONG);

common_param.h

@@ -54,8 +54,8 @@ typedef struct {
   int bgemm_unroll_m, bgemm_unroll_n, bgemm_unroll_mn;
   int bgemm_align_k;
 
-  int    (*bgemm_kernel   )(BLASLONG, BLASLONG, BLASLONG, bfloat16, bfloat16 *, bfloat16 *, bfloat16 *, BLASLONG);
-  int    (*bgemm_beta     )(BLASLONG, BLASLONG, BLASLONG, bfloat16, bfloat16 *, BLASLONG, bfloat16 *, BLASLONG, bfloat16 *, BLASLONG);
+  int    (*bgemm_kernel   )(BLASLONG, BLASLONG, BLASLONG, float, bfloat16 *, bfloat16 *, bfloat16 *, BLASLONG);
+  int    (*bgemm_beta     )(BLASLONG, BLASLONG, BLASLONG, float, bfloat16 *, BLASLONG, bfloat16 *, BLASLONG, bfloat16 *, BLASLONG);
 
   int    (*bgemm_incopy   )(BLASLONG, BLASLONG, bfloat16 *, BLASLONG, bfloat16 *);
   int    (*bgemm_itcopy   )(BLASLONG, BLASLONG, bfloat16 *, BLASLONG, bfloat16 *);

driver/level3/Makefile

@@ -52,6 +52,13 @@ ifeq ($(BUILD_BFLOAT16),1)
 SBBLASOBJS       += sbgemm_nn.$(SUFFIX) sbgemm_nt.$(SUFFIX) sbgemm_tn.$(SUFFIX) sbgemm_tt.$(SUFFIX)
 endif
 
+ifeq ($(BUILD_BFLOAT16_ONLY),1)
+BBLASOBJS       += bgemm_nn.$(SUFFIX) bgemm_nt.$(SUFFIX) bgemm_tn.$(SUFFIX) bgemm_tt.$(SUFFIX)
+endif
+
+BLASOBJS	+= \
+	gemm_nn.$(SUFFIX) gemm_nt.$(SUFFIX) gemm_tn.$(SUFFIX) gemm_tt.$(SUFFIX)
+
 SBLASOBJS	+= \
 	sgemm_nn.$(SUFFIX) sgemm_nt.$(SUFFIX) sgemm_tn.$(SUFFIX) sgemm_tt.$(SUFFIX) \
 	strmm_LNUU.$(SUFFIX) strmm_LNUN.$(SUFFIX) strmm_LNLU.$(SUFFIX) strmm_LNLN.$(SUFFIX) \
@@ -376,6 +383,18 @@ endif
 
 all ::
 
+bgemm_nn.$(SUFFIX) : gemm.c level3.c ../../param.h
+	$(CC) $(CFLAGS) $(BLOCKS) -c -DHALF -UDOUBLE -UCOMPLEX -DNN $< -o $(@F)
+
+bgemm_nt.$(SUFFIX) : gemm.c level3.c ../../param.h
+	$(CC) $(CFLAGS) $(BLOCKS) -c -DHALF -UDOUBLE -UCOMPLEX -DNT $< -o $(@F)
+
+bgemm_tn.$(SUFFIX) : gemm.c level3.c ../../param.h
+	$(CC) $(CFLAGS) $(BLOCKS) -c -DHALF -UDOUBLE -UCOMPLEX -DTN $< -o $(@F)
+
+bgemm_tt.$(SUFFIX) : gemm.c level3.c ../../param.h
+	$(CC) $(CFLAGS) $(BLOCKS) -c -DHALF -UDOUBLE -UCOMPLEX -DTT $< -o $(@F)
+
 sbgemm_nn.$(SUFFIX) : gemm.c level3.c ../../param.h
 	$(CC) $(CFLAGS) $(BLOCKS) -c -DHALF -UDOUBLE -UCOMPLEX -DNN $< -o $(@F)
 
@@ -432,8 +451,8 @@ cgemm_nt.$(SUFFIX) : gemm.c level3.c  ../../param.h
 
 cgemm_nr.$(SUFFIX) : gemm.c level3.c  ../../param.h
 	$(CC) $(CFLAGS) $(BLOCKS) -c -UDOUBLE -DCOMPLEX -DNR $< -o $(@F)
-
 cgemm_nc.$(SUFFIX) : gemm.c level3.c  ../../param.h
+
 	$(CC) $(CFLAGS) $(BLOCKS) -c -UDOUBLE -DCOMPLEX -DNC $< -o $(@F)
 
 cgemm_tn.$(SUFFIX) : gemm.c level3.c  ../../param.h

driver/level3/level3.c

@@ -43,9 +43,11 @@
 #if !defined(XDOUBLE) || !defined(QUAD_PRECISION)
 #ifndef COMPLEX
 #define BETA_OPERATION(M_FROM, M_TO, N_FROM, N_TO, BETA, C, LDC) \
-	GEMM_BETA((M_TO) - (M_FROM), (N_TO - N_FROM), 0, \
-		  BETA[0], NULL, 0, NULL, 0, \
-		  (FLOAT *)(C) + ((M_FROM) + (N_FROM) * (LDC)) * COMPSIZE, LDC)
+  do {                                                                        \
+    GEMM_BETA((M_TO) - (M_FROM), (N_TO - N_FROM), 0,                          \
+              BETA[0], NULL, 0, NULL, 0,                                      \
+              (FLOAT *)(C) + ((M_FROM) + (N_FROM) * (LDC)) * COMPSIZE, LDC);  \
+  } while (0)
 #else
 #define BETA_OPERATION(M_FROM, M_TO, N_FROM, N_TO, BETA, C, LDC) \
 	GEMM_BETA((M_TO) - (M_FROM), (N_TO - N_FROM), 0, \
@@ -189,7 +191,11 @@
 int CNAME(blas_arg_t *args, BLASLONG *range_m, BLASLONG *range_n,
 		  XFLOAT *sa, XFLOAT *sb, BLASLONG dummy){
   BLASLONG k, lda, ldb, ldc;
+#if defined(BUILD_BFLOAT16_ONLY)
+  float *alpha, *beta;
+#else  
   FLOAT *alpha, *beta;
+#endif
   IFLOAT *a, *b;
   FLOAT *c;
   BLASLONG m_from, m_to, n_from, n_to;
@@ -224,8 +230,14 @@ int CNAME(blas_arg_t *args, BLASLONG *range_m, BLASLONG *range_n,
   ldb = LDB;
   ldc = LDC;
 
+#if defined(BUILD_BFLOAT16_ONLY)
+  alpha = (float *)args -> alpha;
+  beta  = (float *)args -> beta;
+#else  
   alpha = (FLOAT *)args -> alpha;
   beta  = (FLOAT *)args -> beta;
+#endif
+
 
   m_from = 0;
   m_to   = M;

driver/level3/level3_thread.c

@@ -239,7 +239,11 @@ static int inner_thread(blas_arg_t *args, BLASLONG *range_m, BLASLONG *range_n,
   BLASLONG k, lda, ldb, ldc;
   BLASLONG m_from, m_to, n_from, n_to;
 
+#if defined(BUILD_BFLOAT16_ONLY)
+  float *alpha, *beta;
+#else  
   FLOAT *alpha, *beta;
+#endif
   IFLOAT *a, *b;
   FLOAT *c;
   job_t *job = (job_t *)args -> common;
@@ -277,8 +281,14 @@ static int inner_thread(blas_arg_t *args, BLASLONG *range_m, BLASLONG *range_n,
   ldb = LDB;
   ldc = LDC;
 
+#if defined(BUILD_BFLOAT16_ONLY)
+  alpha = (float *)args -> alpha;
+  beta  = (float *)args -> beta;
+#else  
   alpha = (FLOAT *)args -> alpha;
   beta  = (FLOAT *)args -> beta;
+#endif
+
 
   /* Initialize 2D CPU distribution */
   nthreads_m = args -> nthreads;

interface/Makefile

@@ -53,6 +53,10 @@ SBBLAS3OBJS    = sbgemm.$(SUFFIX) sbgemmt.$(SUFFIX) sbgemmtr.$(SUFFIX)
 SBEXTOBJS      = sbstobf16.$(SUFFIX) sbdtobf16.$(SUFFIX) sbf16tos.$(SUFFIX) dbf16tod.$(SUFFIX)
 endif
 
+ifeq ($(BUILD_BFLOAT16_ONLY), 1)
+BBLAS3OBJ = bgemm.$(SUFFIX)
+endif
+
 DBLAS1OBJS    = \
 		daxpy.$(SUFFIX) dswap.$(SUFFIX) \
 		dcopy.$(SUFFIX) dscal.$(SUFFIX) \
@@ -291,6 +295,10 @@ CSBBLAS3OBJS = cblas_sbgemm.$(SUFFIX) cblas_sbgemmt.$(SUFFIX) cblas_sbgemmtr.$(S
 CSBEXTOBJS   = cblas_sbstobf16.$(SUFFIX) cblas_sbdtobf16.$(SUFFIX) cblas_sbf16tos.$(SUFFIX) cblas_dbf16tod.$(SUFFIX)
 endif
 
+ifeq ($(BUILD_BFLOAT16_ONLY), 1)
+CBBLAS3OBJS = cblas_bgemm.$(SUFFIX)
+endif
+
 CDBLAS1OBJS   = \
 	cblas_idamax.$(SUFFIX) cblas_idamin.$(SUFFIX) cblas_dasum.$(SUFFIX) cblas_daxpy.$(SUFFIX) \
 	cblas_dcopy.$(SUFFIX) cblas_ddot.$(SUFFIX) \
@@ -388,6 +396,7 @@ SBLAS3OBJS   += $(CSBLAS3OBJS)
 SBBLAS1OBJS  += $(CSBBLAS1OBJS)
 SBBLAS2OBJS  += $(CSBBLAS2OBJS)
 SBBLAS3OBJS  += $(CSBBLAS3OBJS)
+BBLAS3OBJ    += $(CBBLAS3OBJS)
 DBLAS1OBJS   += $(CDBLAS1OBJS)
 DBLAS2OBJS   += $(CDBLAS2OBJS)
 DBLAS3OBJS   += $(CDBLAS3OBJS)
@@ -403,6 +412,7 @@ SBEXTOBJS     += $(CSBEXTOBJS)
 CBAUXOBJS += $(CXERBLAOBJ)
 endif
 
+BBLASOBJS    = $(BBLAS3OBJ)
 SBLASOBJS    = $(SBLAS1OBJS) $(SBLAS2OBJS) $(SBLAS3OBJS)
 SBBLASOBJS   = $(SBBLAS1OBJS) $(SBBLAS2OBJS) $(SBBLAS3OBJS)
 DBLASOBJS    = $(DBLAS1OBJS) $(DBLAS2OBJS) $(DBLAS3OBJS)
@@ -550,7 +560,7 @@ level1 : $(SBEXTOBJS) $(SBBLAS1OBJS) $(SBLAS1OBJS) $(DBLAS1OBJS) $(QBLAS1OBJS) $
 level2 : $(SBBLAS2OBJS) $(SBLAS2OBJS) $(DBLAS2OBJS) $(QBLAS2OBJS) $(CBLAS2OBJS) $(ZBLAS2OBJS) $(XBLAS2OBJS)
 	$(AR) $(ARFLAGS) -ru $(TOPDIR)/$(LIBNAME) $^
 
-level3 : $(SBBLAS3OBJS) $(SBLAS3OBJS) $(DBLAS3OBJS) $(QBLAS3OBJS) $(CBLAS3OBJS) $(ZBLAS3OBJS) $(XBLAS3OBJS) 
+level3 : $(BBLAS3OBJ) $(SBBLAS3OBJS) $(SBLAS3OBJS) $(DBLAS3OBJS) $(QBLAS3OBJS) $(CBLAS3OBJS) $(ZBLAS3OBJS) $(XBLAS3OBJS) 
 	$(AR) $(ARFLAGS) -ru $(TOPDIR)/$(LIBNAME) $^
 
 aux :	$(CBAUXOBJS)
@@ -1309,6 +1319,11 @@ sbgemmtr.$(SUFFIX) sbgemmtr.$(PSUFFIX) : sbgemmt.c ../param.h
 	$(CC) -c $(CFLAGS) -DRNAME $< -o $(@F)
 endif
 
+ifeq ($(BUILD_BFLOAT16_ONLY), 1)
+bgemm.$(SUFFIX) : gemm.c ../param.h
+	$(CC) -c $(CFLAGS) $< -o $(@F)
+endif
+
 sgemm.$(SUFFIX) sgemm.$(PSUFFIX) : gemm.c ../param.h
 	$(CC) -c $(CFLAGS) $< -o $(@F)
 
@@ -1968,6 +1983,11 @@ cblas_sbgemm.$(SUFFIX) cblas_sbgemm.$(PSUFFIX) : gemm.c ../param.h
 	$(CC) -DCBLAS -c $(CFLAGS) $< -o $(@F)
 endif
 
+ifeq ($(BUILD_BFLOAT16_ONLY),1)
+cblas_bgemm.$(SUFFIX) cblas_bgemm.$(PSUFFIX) : gemm.c ../param.h
+	$(CC) -DCBLAS -c $(CFLAGS) $< -o $(@F)
+endif
+
 cblas_dgemm.$(SUFFIX) cblas_dgemm.$(PSUFFIX) : gemm.c ../param.h
 	$(CC) -DCBLAS -c $(CFLAGS) $< -o $(@F)
 

interface/gemm.c

@@ -250,6 +250,15 @@ static inline int get_gemm_optimal_nthreads(double MNK) {
 
 #ifndef CBLAS
 
+#ifdef BFLOAT16_ONLY
+void NAME(char *TRANSA, char *TRANSB,
+	  blasint *M, blasint *N, blasint *K,
+	  float *alpha,
+	  IFLOAT *a, blasint *ldA,
+	  IFLOAT *b, blasint *ldB,
+	  float *beta,
+	  FLOAT *c, blasint *ldC){
+#else
 void NAME(char *TRANSA, char *TRANSB,
 	  blasint *M, blasint *N, blasint *K,
 	  FLOAT *alpha,
@@ -257,7 +266,7 @@ void NAME(char *TRANSA, char *TRANSB,
 	  IFLOAT *b, blasint *ldB,
 	  FLOAT *beta,
 	  FLOAT *c, blasint *ldC){
-
+#endif
   blas_arg_t args;
 
   int transa, transb, nrowa, nrowb;
@@ -366,11 +375,19 @@ void NAME(char *TRANSA, char *TRANSB,
 void CNAME(enum CBLAS_ORDER order, enum CBLAS_TRANSPOSE TransA, enum CBLAS_TRANSPOSE TransB,
 	   blasint m, blasint n, blasint k,
 #ifndef COMPLEX
+  #ifdef BFLOAT16_ONLY
+	   float alpha,
+	   IFLOAT *a, blasint lda,
+	   IFLOAT *b, blasint ldb,
+	   float beta,
+	   FLOAT *c, blasint ldc) {
+  #else
 	   FLOAT alpha,
 	   IFLOAT *a, blasint lda,
 	   IFLOAT *b, blasint ldb,
 	   FLOAT beta,
 	   FLOAT *c, blasint ldc) {
+  #endif
 #else
 	   void *valpha,
 	   void *va, blasint lda,

kernel/Makefile.L3

@@ -136,6 +136,25 @@ endif
 endif
 endif
 
+ifeq ($(BUILD_BFLOAT16_ONLY), 1)
+ifndef BGEMMKERNEL
+BGEMM_BETA = ../generic/gemm_beta.c
+BGEMMKERNEL    = ../generic/gemmkernel_2x2.c
+BGEMMINCOPY    = ../generic/gemm_ncopy_2.c
+BGEMMITCOPY    = ../generic/gemm_tcopy_2.c
+BGEMMONCOPY    = ../generic/gemm_ncopy_2.c
+BGEMMOTCOPY    = ../generic/gemm_tcopy_2.c
+BGEMMINCOPYOBJ =  bgemm_incopy$(TSUFFIX).$(SUFFIX)
+BGEMMITCOPYOBJ =  bgemm_itcopy$(TSUFFIX).$(SUFFIX)
+BGEMMONCOPYOBJ =  bgemm_oncopy$(TSUFFIX).$(SUFFIX)
+BGEMMOTCOPYOBJ =  bgemm_otcopy$(TSUFFIX).$(SUFFIX)
+endif
+BKERNELOBJS += \
+	bgemm_kernel$(TSUFFIX).$(SUFFIX) \
+	$(BGEMMINCOPYOBJ) $(BGEMMITCOPYOBJ) \
+	$(BGEMMONCOPYOBJ) $(BGEMMOTCOPYOBJ)	
+endif
+
 ifeq ($(BUILD_BFLOAT16), 1)
 ifndef SBGEMMKERNEL
 SBGEMM_BETA = ../generic/gemm_beta.c
@@ -216,6 +235,11 @@ XKERNELOBJS	+= \
 	$(XGEMMINCOPYOBJ) $(XGEMMITCOPYOBJ) \
 	$(XGEMMONCOPYOBJ) $(XGEMMOTCOPYOBJ)
 
+
+ifeq ($(BUILD_BFLOAT16_ONLY), 1)
+BBLASOBJS += $(BKERNELOBJS)
+endif
+
 ifeq ($(BUILD_BFLOAT16),1)
 SBBLASOBJS      += $(SBKERNELOBJS)
 endif
@@ -226,6 +250,10 @@ CBLASOBJS	+= $(CKERNELOBJS)
 ZBLASOBJS	+= $(ZKERNELOBJS)
 XBLASOBJS	+= $(XKERNELOBJS)
 
+ifeq ($(BUILD_BFLOAT16_ONLY), 1)
+BBLASOBJS += bgemm_beta$(TSUFFIX).$(SUFFIX)
+endif
+
 ifeq ($(BUILD_BFLOAT16),1)
 SBBLASOBJS += sbgemm_beta$(TSUFFIX).$(SUFFIX)
 endif
@@ -651,6 +679,11 @@ XGEMMITCOPYOBJ_P = $(XGEMMITCOPYOBJ:.$(SUFFIX)=.$(PSUFFIX))
 XGEMMONCOPYOBJ_P = $(XGEMMONCOPYOBJ:.$(SUFFIX)=.$(PSUFFIX))
 XGEMMOTCOPYOBJ_P = $(XGEMMOTCOPYOBJ:.$(SUFFIX)=.$(PSUFFIX))
 
+ifeq ($(BUILD_BFLOAT16_ONLY),1)
+$(KDIR)bgemm_beta$(TSUFFIX).$(SUFFIX) : $(KERNELDIR)/$(BGEMM_BETA)
+	$(CC) $(CFLAGS) -c -DBFLOAT16_ONLY -UDOUBLE -UCOMPLEX $< -o $@
+endif
+
 ifeq ($(BUILD_BFLOAT16),1)
 $(KDIR)sbgemm_beta$(TSUFFIX).$(SUFFIX) : $(KERNELDIR)/$(SBGEMM_BETA)
 	$(CC) $(CFLAGS) -c -DBFLOAT16 -UDOUBLE -UCOMPLEX $< -o $@
@@ -678,6 +711,21 @@ ifeq ($(ARCH), E2K)
 USE_TRMM = 1
 endif
 
+ifeq ($(BUILD_BFLOAT16_ONLY), 1)
+
+$(KDIR)$(BGEMMONCOPYOBJ) : $(KERNELDIR)/$(BGEMMONCOPY)
+	$(CC) $(CFLAGS) -c -DBFLOAT16_ONLY -UDOUBLE -UCOMPLEX $< -o $@
+
+$(KDIR)$(BGEMMOTCOPYOBJ) : $(KERNELDIR)/$(BGEMMOTCOPY)
+	$(CC) $(CFLAGS) -c -DBFLOAT16_ONLY -UDOUBLE -UCOMPLEX $< -o $@
+
+$(KDIR)$(BGEMMINCOPYOBJ) : $(KERNELDIR)/$(BGEMMINCOPY)
+	$(CC) $(CFLAGS) -c -DDBFLOAT16_ONLY -UDOUBLE -UCOMPLEX $< -o $@
+
+$(KDIR)$(BGEMMITCOPYOBJ) : $(KERNELDIR)/$(BGEMMITCOPY)
+	$(CC) $(CFLAGS) -c -DDBFLOAT16_ONLY -UDOUBLE -UCOMPLEX $< -o $@
+
+endif
 
 ifeq ($(BUILD_BFLOAT16), 1)
 
@@ -874,6 +922,11 @@ endif
 endif
 endif
 
+ifeq ($(BUILD_BFLOAT16_ONLY), 1)
+$(KDIR)bgemm_kernel$(TSUFFIX).$(SUFFIX) : $(KERNELDIR)/$(BGEMMKERNEL) 
+	$(CC) $(CFLAGS) -c -DBFLOAT16_ONLY -UDOUBLE -UCOMPLEX $< -o $@
+endif
+
 ifeq ($(BUILD_BFLOAT16), 1)
 
 $(KDIR)sbgemm_kernel$(TSUFFIX).$(SUFFIX) : $(KERNELDIR)/$(SBGEMMKERNEL) $(SBGEMMDEPEND)

kernel/arm64/sbgemm_kernel_4x4_neoversev1.c

@@ -35,7 +35,7 @@
 #undef ALPHA_ONE
 #include "sbgemm_kernel_4x4_neoversev1_impl.c"
 
-int CNAME(BLASLONG m, BLASLONG n, BLASLONG k, FLOAT alpha, IFLOAT *A, IFLOAT *B,
+int CNAME(BLASLONG m, BLASLONG n, BLASLONG k, float alpha, IFLOAT *A, IFLOAT *B,
           FLOAT *C, BLASLONG ldc) {
   if (alpha == 1.0f)
     return sbgemm_kernel_neoversev1_alpha_one(m, n, k, alpha, A, B, C, ldc);

kernel/arm64/sbgemm_kernel_4x4_neoversev1_impl.c

@@ -78,11 +78,11 @@
 
 #ifdef ALPHA_ONE
 int sbgemm_kernel_neoversev1_alpha_one(BLASLONG m, BLASLONG n, BLASLONG k,
-                                       FLOAT alpha, IFLOAT *A, IFLOAT *B,
+                                       float alpha, IFLOAT *A, IFLOAT *B,
                                        FLOAT *C, BLASLONG ldc)
 #else
 int sbgemm_kernel_neoversev1_alpha(BLASLONG m, BLASLONG n, BLASLONG k,
-                                   FLOAT alpha, IFLOAT *A, IFLOAT *B, FLOAT *C,
+                                   float alpha, IFLOAT *A, IFLOAT *B, FLOAT *C,
                                    BLASLONG ldc)
 #endif
 {

kernel/generic/bgemmkernel_2x2.c

@@ -1,227 +0,0 @@
-/***************************************************************************
- * Copyright (c) 2025, The OpenBLAS Project
- * All rights reserved.
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in
- * the documentation and/or other materials provided with the
- * distribution.
- * 3. Neither the name of the OpenBLAS project nor the names of
- * its contributors may be used to endorse or promote products
- * derived from this software without specific prior written permission.
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE OPENBLAS PROJECT OR CONTRIBUTORS BE
- * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
- * *****************************************************************************/
-
-#include "common.h"
-
-static float bfloat16tof32(bfloat16 f16) {
-  float result = 0;
-  unsigned short *q = (unsigned short *)(&result);
-#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
-  q[0] = f16;
-#else
-  q[1] = f16;
-#endif
-  return result;
-}
-
-static bfloat16 f32tobfloat16(float f32) {
-  unsigned short *q = (unsigned short *)(&f32);
-#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
-  return q[0];
-#else
-  return q[1];
-#endif
-}
-
-#define BF16TOF32(x) (bfloat16tof32(x))
-#define F32TOBF16(x) (f32tobfloat16(x))
-
-int CNAME(BLASLONG bm, BLASLONG bn, BLASLONG bk, FLOAT alpha, IFLOAT *ba,
-          IFLOAT *bb, FLOAT *C, BLASLONG ldc) {
-  BLASLONG i, j, k;
-  FLOAT *C0, *C1; // bfloat16
-  IFLOAT *ptrba, *ptrbb;
-  float res0, res1, res2, res3;
-  float load0, load1, load2, load3, load4, load5, load6, load7;
-
-  float alpha_ = BF16TOF32(alpha);
-
-  for (j = 0; j < bn / 2; j += 1) {
-    C0 = C;
-    C1 = C0 + ldc;
-    ptrba = ba;
-    for (i = 0; i < bm / 2; i += 1) {
-      ptrbb = bb;
-      res0 = 0;
-      res1 = 0;
-      res2 = 0;
-      res3 = 0;
-      for (k = 0; k < bk / 4; k += 1) {
-        load0 = BF16TOF32(ptrba[2 * 0 + 0]);
-        load2 = BF16TOF32(ptrba[2 * 0 + 1]);
-        load4 = BF16TOF32(ptrba[2 * 1 + 0]);
-        load6 = BF16TOF32(ptrba[2 * 1 + 1]);
-
-        load1 = BF16TOF32(ptrbb[2 * 0 + 0]);
-        load3 = BF16TOF32(ptrbb[2 * 0 + 1]);
-        load5 = BF16TOF32(ptrbb[2 * 1 + 0]);
-        load7 = BF16TOF32(ptrbb[2 * 1 + 1]);
-
-        res0 = res0 + load0 * load1;
-        res1 = res1 + load2 * load1;
-        res2 = res2 + load0 * load3;
-        res3 = res3 + load2 * load3;
-
-        res0 = res0 + load4 * load5;
-        res1 = res1 + load6 * load5;
-        res2 = res2 + load4 * load7;
-        res3 = res3 + load6 * load7;
-
-        load0 = BF16TOF32(ptrba[2 * 2 + 0]);
-        load2 = BF16TOF32(ptrba[2 * 2 + 1]);
-        load4 = BF16TOF32(ptrba[2 * 3 + 0]);
-        load6 = BF16TOF32(ptrba[2 * 3 + 1]);
-
-        load1 = BF16TOF32(ptrbb[2 * 2 + 0]);
-        load3 = BF16TOF32(ptrbb[2 * 2 + 1]);
-        load5 = BF16TOF32(ptrbb[2 * 3 + 0]);
-        load7 = BF16TOF32(ptrbb[2 * 3 + 1]);
-
-        res0 = res0 + load0 * load1;
-        res1 = res1 + load2 * load1;
-        res2 = res2 + load0 * load3;
-        res3 = res3 + load2 * load3;
-
-        res0 = res0 + load4 * load5;
-        res1 = res1 + load6 * load5;
-        res2 = res2 + load4 * load7;
-        res3 = res3 + load6 * load7;
-      }
-
-      for (k = 0; k < (bk & 3); k += 1) {
-        load0 = BF16TOF32(ptrba[2 * 0 + 0]);
-        load2 = BF16TOF32(ptrba[2 * 0 + 1]);
-        load1 = BF16TOF32(ptrbb[2 * 0 + 0]);
-        load3 = BF16TOF32(ptrbb[2 * 0 + 1]);
-
-        res0 = res0 + load0 * load1;
-        res1 = res1 + load2 * load1;
-        res2 = res2 + load0 * load3;
-        res3 = res3 + load2 * load3;
-
-        ptrba = ptrba + 2;
-        ptrbb = ptrbb + 2;
-      }
-
-      res0 = res0 * alpha_ + BF16TOF32(C0[0]);
-      res1 = res1 * alpha_ + BF16TOF32(C0[1]);
-      res2 = res2 * alpha_ + BF16TOF32(C1[0]);
-      res3 = res3 * alpha_ + BF16TOF32(C1[1]);
-
-      C0[0] = F32TOBF16(res0);
-      C0[1] = F32TOBF16(res1);
-      C1[0] = F32TOBF16(res2);
-      C1[1] = F32TOBF16(res3);
-
-      C0 = C0 + 2;
-      C1 = C1 + 2;
-    }
-
-    for (i = 0; i < (bm & 1); i += 1) {
-      ptrbb = bb;
-      res0 = 0;
-      res1 = 0;
-      for (k = 0; k < bk; k += 1) {
-        load0 = BF16TOF32(ptrba[0 + 0]);
-        load1 = BF16TOF32(ptrbb[2 * 0 + 0]);
-        load2 = BF16TOF32(ptrbb[2 * 0 + 1]);
-
-        res0 = res0 + load0 * load1;
-        res1 = res1 + load0 * load2;
-
-        ptrba = ptrba + 1;
-        ptrbb = ptrbb + 2;
-      }
-
-      res0 = res0 * alpha_ + BF16TOF32(C0[0]);
-      res1 = res1 * alpha_ + BF16TOF32(C1[0]);
-
-      C0[0] = res0;
-      C1[0] = res1;
-
-      C0 = C0 + 1;
-      C1 = C1 + 1;
-    }
-
-    k = (bk << 1);
-    bb = bb + k;
-    i = (ldc << 1);
-    C = C + i;
-  }
-
-  for (j = 0; j < (bn & 1); j += 1) {
-    C0 = C;
-    ptrba = ba;
-    for (i = 0; i < bm / 2; i += 1) {
-      ptrbb = bb;
-      res0 = 0;
-      res1 = 0;
-      for (k = 0; k < bk; k += 1) {
-        load0 = BF16TOF32(ptrba[2 * 0 + 0]);
-        load2 = BF16TOF32(ptrba[2 * 0 + 1]);
-
-        load1 = BF16TOF32(ptrbb[0 + 0]);
-
-        res0 = res0 + load0 * load1;
-        res1 = res1 + load2 * load1;
-
-        ptrba = ptrba + 2;
-        ptrbb = ptrbb + 1;
-      }
-
-      res0 = res0 * alpha_ + BF16TOF32(C0[0]);
-      res1 = res1 * alpha_ + BF16TOF32(C0[1]);
-
-      C0[0] = F32TOBF16(res0);
-      C0[1] = F32TOBF16(res1);
-      C0 = C0 + 2;
-    }
-
-    for (i = 0; i < (bm & 1); i += 1) {
-      ptrbb = bb;
-      res0 = 0;
-      for (k = 0; k < bk; k += 1) {
-        load0 = BF16TOF32(ptrba[0 + 0]);
-        load1 = BF16TOF32(ptrbb[0 + 0]);
-        res0 += load0 * load1;
-        ptrba = ptrba + 1;
-        ptrbb = ptrbb + 1;
-      }
-
-      res0 = res0 * alpha_ + BF16TOF32(C0[0]);
-      C0[0] = F32TOBF16(res0);
-      C0 = C0 + 1;
-    }
-
-    k = (bk << 0);
-    bb = bb + k;
-    C = C + ldc;
-  }
-
-  return 0;
-}

kernel/generic/gemm_beta.c

@@ -71,11 +71,15 @@ f32tobfloat16(float f32)
 #define F32TOBF16(x) x
 #endif
 
-
-int CNAME(BLASLONG m, BLASLONG n, BLASLONG dummy1, FLOAT beta_in,
+#if defined(BFLOAT16_ONLY)
+int CNAME(BLASLONG m, BLASLONG n, BLASLONG dummy1, float beta,
 	  IFLOAT *dummy2, BLASLONG dummy3, IFLOAT *dummy4, BLASLONG dummy5,
 	  FLOAT *c, BLASLONG ldc){
-
+#else
+int CNAME(BLASLONG m, BLASLONG n, BLASLONG dummy1, FLOAT beta,
+	  IFLOAT *dummy2, BLASLONG dummy3, IFLOAT *dummy4, BLASLONG dummy5,
+	  FLOAT *c, BLASLONG ldc){
+#endif
 
   BLASLONG i, j;
   BLASLONG chunk, remain;
@@ -83,25 +87,24 @@ int CNAME(BLASLONG m, BLASLONG n, BLASLONG dummy1, FLOAT beta_in,
   c_offset = c;
   chunk = m >> 3;
   remain = m & 7;
-  float beta = BF16TOF32(beta_in);
 
   if (beta == ZERO){
 	  for(j=n; j>0; j--){
 		c_offset1 = c_offset;
 		c_offset += ldc;
 		for(i=chunk; i>0; i--){
-			*(c_offset1 + 0) = ZERO;
-			*(c_offset1 + 1) = ZERO;
-			*(c_offset1 + 2) = ZERO;
-			*(c_offset1 + 3) = ZERO;
-			*(c_offset1 + 4) = ZERO;
-			*(c_offset1 + 5) = ZERO;
-			*(c_offset1 + 6) = ZERO;
-			*(c_offset1 + 7) = ZERO;
+			*(c_offset1 + 0) = F32TOBF16(ZERO);
+			*(c_offset1 + 1) = F32TOBF16(ZERO);
+			*(c_offset1 + 2) = F32TOBF16(ZERO);
+			*(c_offset1 + 3) = F32TOBF16(ZERO);
+			*(c_offset1 + 4) = F32TOBF16(ZERO);
+			*(c_offset1 + 5) = F32TOBF16(ZERO);
+			*(c_offset1 + 6) = F32TOBF16(ZERO);
+			*(c_offset1 + 7) = F32TOBF16(ZERO);
 			c_offset1 += 8;
 		}
 		for(i=remain; i>0; i--){
-			*c_offset1 = ZERO;
+			*c_offset1 = F32TOBF16(ZERO);
 			c_offset1 ++;
 		}
 	  }

kernel/generic/gemmkernel_2x2.c

@@ -1,5 +1,32 @@
+/***************************************************************************
+Copyright (c) 2025 The OpenBLAS Project
+All rights reserved.
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+1. Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+2. Redistributions in binary form must reproduce the above copyright
+notice, this list of conditions and the following disclaimer in
+the documentation and/or other materials provided with the
+distribution.
+3. Neither the name of the OpenBLAS project nor the names of
+its contributors may be used to endorse or promote products
+derived from this software without specific prior written permission.
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL THE OPENBLAS PROJECT OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
+GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*****************************************************************************/
+
 #include "common.h"
-#if defined(BFLOAT16) && defined(BFLOAT16CONVERSION)
+#if (defined(BFLOAT16) || defined(BFLOAT16_ONLY))&& defined(BFLOAT16CONVERSION)
 static float
 bfloat16tof32 (bfloat16 f16)
 {
@@ -12,12 +39,29 @@ bfloat16tof32 (bfloat16 f16)
 #endif
   return result;
 }
+
+static bfloat16 f32tobfloat16(float f32) {
+  unsigned short *q = (unsigned short *)(&f32);
+#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+  return q[0];
+#else
+  return q[1];
+#endif
+}
+
 #define BF16TOF32(x) (bfloat16tof32(x))
+#define F32TOBF16(x) (f32tobfloat16(x))
 #else
 #define BF16TOF32(x) x
+#define F32TOBF16(x) x
 #endif
+
+#ifdef BFLOAT16_ONLY
+int CNAME(BLASLONG bm,BLASLONG bn,BLASLONG bk, float alpha,IFLOAT* ba,IFLOAT* bb,FLOAT* C,BLASLONG ldc
+#else
 int CNAME(BLASLONG bm,BLASLONG bn,BLASLONG bk,FLOAT alpha,IFLOAT* ba,IFLOAT* bb,FLOAT* C,BLASLONG ldc
-#ifdef TRMMKERNEL
+#endif
+  #ifdef TRMMKERNEL
 		,BLASLONG offset
 #endif
 		)
@@ -90,13 +134,17 @@ int CNAME(BLASLONG bm,BLASLONG bn,BLASLONG bk,FLOAT alpha,IFLOAT* ba,IFLOAT* bb,
                   ptrbb = ptrbb+2;
                }
              res0 = res0*alpha;
-             C0[0] = C0[0]+res0;
+             C0[0] = F32TOBF16(BF16TOF32(C0[0])+res0);
+             //printf("i = %d, j = %d, r = %.2f\n", i, j , BF16TOF32(C0[0]));
              res1 = res1*alpha;
-             C0[1] = C0[1]+res1;
+             C0[1] = F32TOBF16(BF16TOF32(C0[1])+res1);
+             //printf("i = %d, j = %d, r = %.2f\n", i, j , BF16TOF32(C0[1]));
              res2 = res2*alpha;
-             C1[0] = C1[0]+res2;
+             C1[0] = F32TOBF16(BF16TOF32(C1[0])+res2);
+             //printf("i = %d, j = %d, r = %.2f\n", i, j , BF16TOF32(C1[0]));
              res3 = res3*alpha;
-             C1[1] = C1[1]+res3;
+             C1[1] = F32TOBF16(BF16TOF32(C1[1])+res3);
+             //printf("i = %d, j = %d, r = %.2f\n", i, j , BF16TOF32(C1[1]));
              C0 = C0+2;
              C1 = C1+2;
           }
@@ -116,9 +164,11 @@ int CNAME(BLASLONG bm,BLASLONG bn,BLASLONG bk,FLOAT alpha,IFLOAT* ba,IFLOAT* bb,
                   ptrbb = ptrbb+2;
                }
              res0 = res0*alpha;
-             C0[0] = C0[0]+res0;
+             C0[0] = F32TOBF16(BF16TOF32(C0[0])+res0);
+             //printf("i = %d, j = %d, r = %.2f\n", i, j , BF16TOF32(C0[0]));
              res1 = res1*alpha;
-             C1[0] = C1[0]+res1;
+             C1[0] = F32TOBF16(BF16TOF32(C1[1])+res1);
+             //printf("i = %d, j = %d, r = %.2f\n", i, j , BF16TOF32(C1[0]));
              C0 = C0+1;
              C1 = C1+1;
           }
@@ -147,9 +197,11 @@ int CNAME(BLASLONG bm,BLASLONG bn,BLASLONG bk,FLOAT alpha,IFLOAT* ba,IFLOAT* bb,
                   ptrbb = ptrbb+1;
                }
              res0 = res0*alpha;
-             C0[0] = C0[0]+res0;
+             C0[0] = F32TOBF16(BF16TOF32(C0[0])+res0);
+             //printf("i = %d, j = %d, r = %.2f\n", i, j , BF16TOF32(C0[0]));
              res1 = res1*alpha;
-             C0[1] = C0[1]+res1;
+             C0[1] = F32TOBF16(BF16TOF32(C0[1])+res1);
+             //printf("i = %d, j = %d, r = %.2f\n", i, j , BF16TOF32(C0[1]));
              C0 = C0+2;
           }
         for (i=0; i<(bm&1); i+=1)
@@ -165,7 +217,8 @@ int CNAME(BLASLONG bm,BLASLONG bn,BLASLONG bk,FLOAT alpha,IFLOAT* ba,IFLOAT* bb,
                   ptrbb = ptrbb+1;
                }
              res0 = res0*alpha;
-             C0[0] = C0[0]+res0;
+             C0[0] = F32TOBF16(BF16TOF32(C0[0])+res0);
+             //printf("i = %d, j = %d, r = %.2f\n", i, j , BF16TOF32(C0[0]));
              C0 = C0+1;
           }
         k = (bk<<0);

test/Makefile

@@ -1,3 +1,31 @@
+###############################################################################
+# Copyright (c) 2025, The OpenBLAS Project
+# All rights reserved.
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in
+#    the documentation and/or other materials provided with the
+#    distribution.
+# 3. Neither the name of the OpenBLAS project nor the names of
+#    its contributors may be used to endorse or promote products
+#    derived from this software without specific prior written permission.
+# 
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED. IN NO EVENT SHALL THE OPENBLAS PROJECT OR CONTRIBUTORS BE
+# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+###############################################################################
 TOPDIR	= ..
 include ../Makefile.system
 ifeq ($(F_COMPILER),GFORTRAN)
@@ -164,6 +192,9 @@ endif
 endif
 endif
 
+ifeq ($(BUILD_BFLOAT16_ONLY),1)
+BF3= test_bgemm
+endif
 ifeq ($(BUILD_BFLOAT16),1)
 B3= test_sbgemm
 endif
@@ -192,11 +223,15 @@ endif
 ifeq ($(SUPPORT_GEMM3M),1)
 level3: $(B3) $(S3) $(D3) $(C3) $(Z3) level3_3m
 else
-level3: $(B3) $(S3) $(D3) $(C3) $(Z3)
+level3: $(BF3) $(B3) $(S3) $(D3) $(C3) $(Z3)
 endif
 
 ifneq ($(CROSS), 1)
 	rm -f ?BLAT3.SUMM
+ifeq ($(BUILD_BFLOAT16_ONLY),1)
+	OPENBLAS_NUM_THREADS=1 OMP_NUM_THREADS=1 ./test_bgemm > BBLAT3.SUMM
+	@$(GREP) -q FATAL SBBLAT3.SUMM && cat BBLAT3.SUMM || exit 0
+endif
 ifeq ($(BUILD_BFLOAT16),1)
 	OPENBLAS_NUM_THREADS=1 OMP_NUM_THREADS=1 ./test_sbgemm > SBBLAT3.SUMM
 	@$(GREP) -q FATAL SBBLAT3.SUMM && cat SBBLAT3.SUMM || exit 0
@@ -366,6 +401,11 @@ zblat3 : zblat3.$(SUFFIX) ../$(LIBNAME)
 	$(FC) $(FLDFLAGS) -o zblat3 zblat3.$(SUFFIX) ../$(LIBNAME) $(EXTRALIB) $(CEXTRALIB)
 endif
 
+ifeq ($(BUILD_BFLOAT16_ONLY),1)
+test_bgemm : compare_sgemm_bgemm.c ../$(LIBNAME)
+	$(CC) $(CLDFLAGS) -o test_bgemm compare_sgemm_bgemm.c ../$(LIBNAME) $(EXTRALIB) $(CEXTRALIB)
+endif
+
 ifeq ($(BUILD_BFLOAT16),1)
 test_sbgemm : compare_sgemm_sbgemm.c ../$(LIBNAME)
 	$(CC) $(CLDFLAGS) -o test_sbgemm compare_sgemm_sbgemm.c ../$(LIBNAME) $(EXTRALIB) $(CEXTRALIB)
@@ -387,7 +427,7 @@ clean:
 	@rm -f *.$(SUFFIX) *.$(PSUFFIX) gmon.$(SUFFIX)ut *.SUMM *.cxml *.exe *.pdb *.dwf \
 	sblat1 dblat1 cblat1 zblat1 \
 	sblat2 dblat2 cblat2 zblat2 \
-	test_sbgemm sblat3 dblat3 cblat3 zblat3 \
+	test_bgemm test_sbgemm sblat3 dblat3 cblat3 zblat3 \
 	sblat1p dblat1p cblat1p zblat1p \
 	sblat2p dblat2p cblat2p zblat2p \
 	sblat3p dblat3p cblat3p zblat3p \

test/compare_sgemm_bgemm.c

@@ -57,10 +57,8 @@ int main(int argc, char *argv[]) {
   char transA = 'N', transB = 'N';
 
   float alpha = 1.0, beta = 0.0;
-  bfloat16 alpha_bf16 = convert_to_bf16(alpha),
-           beta_bf16 = convert_to_bf16(beta);
 
-  for (x = 1; x <= BGEMM_LARGEST; x++) {
+  for (x = 1; x <= loop; x++) {
     if ((x > 100) && (x != BGEMM_LARGEST))
       continue;
     m = k = n = x;
@@ -79,14 +77,14 @@ int main(int argc, char *argv[]) {
 
     for (int i = 0; i < m; i++) {
       for (int j = 0; j < k; j++) {
-        AA[i * k + j] = (i * k + j + 1) % 100;
+        AA[i * k + j] = (i * k + j + 1) % 5;
         A[i * k + j] = AA[i * k + j];
       }
     }
 
     for (int i = 0; i < n; i++) {
       for (int j = 0; j < k; j++) {
-        BB[i * k + j] = (i * k + j + 1) % 100;
+        BB[i * k + j] = (i * k + j + 1) % 5;
         B[i * k + j] = BB[i * k + j];
       }
     }
@@ -102,23 +100,73 @@ int main(int argc, char *argv[]) {
       } else {
         transB = 'T';
       }
+      // printf("******** x = %d, y = %d********\n", x, y);
+      // printf("Matrix AA (m x k):\n");
+      // for (int i = 0; i < m; i++) {
+      //   for (int j = 0; j < k; j++) {
+      //     printf("%.2f ", (float)AA[i * k + j]);  // or %4.1f if float
+      //   }
+      //   printf("\n");
+      // }
+
+      // printf("Matrix A (copy of AA):\n");
+      // for (int i = 0; i < m; i++) {
+      //   for (int j = 0; j < k; j++) {
+      //     printf("%.2f ", A[i * k + j]);
+      //   }
+      //   printf("\n");
+      // }
+
+      // printf("Matrix BB (n x k):\n");
+      // for (int i = 0; i < n; i++) {
+      //   for (int j = 0; j < k; j++) {
+      //     printf("%.2f ", (float)BB[i * k + j]);
+      //   }
+      //   printf("\n");
+      // }
+
+      // printf("Matrix B (copy of BB):\n");
+      // for (int i = 0; i < n; i++) {
+      //   for (int j = 0; j < k; j++) {
+      //     printf("%.2f ", B[i * k + j]);
+      //   }
+      //   printf("\n");
+      // }
 
       memset(C, 0, m * n * sizeof(FLOAT));
       memset(CC, 0, m * n * sizeof(bfloat16));
-      SGEMM(&transA, &transB, &m, &n, &k, &alpha_bf16, A, &m, B, &k, &beta_bf16,
+      SGEMM(&transA, &transB, &m, &n, &k, &alpha, A, &m, B, &k, &beta,
             C, &m);
       BGEMM(&transA, &transB, &m, &n, &k, &alpha, (bfloat16 *)AA, &m,
             (bfloat16 *)BB, &k, &beta, (bfloat16 *)CC, &m);
+      
+
+      // printf("Matrix CC (n x m):\n");
+      // for (int i = 0; i < n; i++) {
+      //   for (int j = 0; j < m; j++) {
+      //     printf("%.2f ", (float)CC[i * m + j]);
+      //   }
+      //   printf("\n");
+      // }
+
+      // printf("Matrix C :\n");
+      // for (int i = 0; i < n; i++) {
+      //   for (int j = 0; j < k; j++) {
+      //     printf("%.2f ", C[i * k + j]);
+      //   }
+      //   printf("\n");
+      // }
 
       for (i = 0; i < n; i++) {
         for (j = 0; j < m; j++) {
-          for (l = 0; l < k; l++) {
-            if (fabs(CC[i * m + j] - C[i * m + j]) > 1.0) {
-              ret++;
+            if (fabs((float)CC[i * m + j] - C[i * m + j]) > 1.0) {
+              ret ++;
             }
-          }
         }
       }
+
+      printf("x = %d, err = %d\n", x, ret);
+      ret = 0;
     }
 
     free(A);