[gcc r15-11423] i386: Correct vdpbf16ps mask usage in pattern [PR126429]

https://gcc.gnu.org/g:e9b1cb64b6e3c10c3d39b8c917d924281c2e7530

commit r15-11423-ge9b1cb64b6e3c10c3d39b8c917d924281c2e7530
Author: Haochen Jiang <[email protected]>
Date:   Tue Jul 28 11:00:38 2026 +0800

    i386: Correct vdpbf16ps mask usage in pattern [PR126429]
    
    512 bit vdpbf16ps is using 16 bit mask. However, it only take the lower 8
    bit into consideration due to avx512fhalfmaskmode usage in pattern.
    
    Correct to avx512fmaskmode and remove not used iterators and patterns.
    256 bit and 128 bit vdpbf16ps are not affected since they are both 8 bit
    mask.
    
    gcc/ChangeLog:
    
            PR target/126429
            * config/i386/sse.md (avx512fmaskhalfmode): Removed.
            (avx512f_dpbf16ps_<mode>_maskz): Use avx512fmaskmode instead of
            avx512fmaskhalfmode.
            (avx512f_dpbf16ps_<mode>_mask): Ditto.
            (avx512f_dpbf16ps_<mode><maskz_half_name>): Rename to ...
            (avx512f_dpbf16ps_<mode><sd_maskz_name>): ... this. Use
            corresponding sd_mask_op4.
            * config/i386/subst.md (maskz_half): Remove not used pattern.
    
    gcc/testsuite/ChangeLog:
    
            PR target/126429
            * gcc.target/i386/pr126429-1.c: New test.
    
    (cherry picked from commit ed04be2c33faaf19d14521f8e6959b12a812701a)

Diff:
---
 gcc/config/i386/sse.md                     | 19 ++++---------------
 gcc/config/i386/subst.md                   | 13 -------------
 gcc/testsuite/gcc.target/i386/pr126429-1.c | 15 +++++++++++++++
 3 files changed, 19 insertions(+), 28 deletions(-)

diff --git a/gcc/config/i386/sse.md b/gcc/config/i386/sse.md
index be51050e4154..1af120b1c6dc 100644
--- a/gcc/config/i386/sse.md
+++ b/gcc/config/i386/sse.md
@@ -1131,17 +1131,6 @@
    (V16SF "hi") (V8SF  "qi") (V4SF  "qi")
    (V8DF  "qi") (V4DF  "qi") (V2DF  "qi")])
 
-;; Mapping of vector modes to corresponding mask half size
-(define_mode_attr avx512fmaskhalfmode
-  [(V64QI "SI") (V32QI "HI") (V16QI "QI")
-   (V32HI "HI") (V16HI "QI") (V8HI  "QI") (V4HI "QI")
-   (V16SI "QI") (V8SI  "QI") (V4SI  "QI")
-   (V8DI  "QI") (V4DI  "QI") (V2DI  "QI")
-   (V32HF "HI") (V16HF "QI") (V8HF  "QI")
-   (V32BF "HI") (V16BF "QI") (V8BF  "QI")
-   (V16SF "QI") (V8SF  "QI") (V4SF  "QI")
-   (V8DF  "QI") (V4DF  "QI") (V2DF  "QI")])
-
 ;; Mapping of vector float modes to an integer mode of the same size
 (define_mode_attr sseintvecmode
   [(V32HF "V32HI") (V32BF "V32HI") (V16SF "V16SI") (V8DF  "V8DI")
@@ -31668,7 +31657,7 @@
    (match_operand:VF1_AVX512VL 1 "register_operand")
    (match_operand:<sf_bf16> 2 "register_operand")
    (match_operand:<sf_bf16> 3 "register_operand")
-   (match_operand:<avx512fmaskhalfmode> 4 "register_operand")]
+   (match_operand:<avx512fmaskmode> 4 "register_operand")]
   "TARGET_AVX512BF16"
 {
   emit_insn (gen_avx512f_dpbf16ps_<mode>_maskz_1(operands[0], operands[1],
@@ -31676,7 +31665,7 @@
   DONE;
 })
 
-(define_insn "avx512f_dpbf16ps_<mode><maskz_half_name>"
+(define_insn "avx512f_dpbf16ps_<mode><sd_maskz_name>"
   [(set (match_operand:VF1_AVX512VL 0 "register_operand" "=v")
 	(unspec:VF1_AVX512VL
 	  [(match_operand:VF1_AVX512VL 1 "register_operand" "0")
@@ -31684,7 +31673,7 @@
 	   (match_operand:<sf_bf16> 3 "nonimmediate_operand" "vm")]
         UNSPEC_VDPBF16PS))]
   "TARGET_AVX512BF16"
-  "vdpbf16ps\t{%3, %2, %0<maskz_half_operand4>|%0<maskz_half_operand4>, %2, %3}")
+  "vdpbf16ps\t{%3, %2, %0<sd_mask_op4>|%0<sd_mask_op4>, %2, %3}")
 
 (define_insn "avx512f_dpbf16ps_<mode>_mask"
   [(set (match_operand:VF1_AVX512VL 0 "register_operand" "=v")
@@ -31695,7 +31684,7 @@
 	     (match_operand:<sf_bf16> 3 "nonimmediate_operand" "vm")]
              UNSPEC_VDPBF16PS)
           (match_dup 1)
-          (match_operand:<avx512fmaskhalfmode> 4 "register_operand" "Yk")))]
+          (match_operand:<avx512fmaskmode> 4 "register_operand" "Yk")))]
   "TARGET_AVX512BF16"
   "vdpbf16ps\t{%3, %2, %0%{%4%}|%0%{%4%}, %2, %3}")
 
diff --git a/gcc/config/i386/subst.md b/gcc/config/i386/subst.md
index c30b274822e9..5d26811f9337 100644
--- a/gcc/config/i386/subst.md
+++ b/gcc/config/i386/subst.md
@@ -469,16 +469,3 @@
 		(const_int 1))
 	     (match_operand:SI 3 "const48_operand")]
 		UNSPEC_EMBEDDED_ROUNDING))])
-
-(define_subst_attr "maskz_half_name" "maskz_half" "" "_maskz_1")
-(define_subst_attr "maskz_half_operand4" "maskz_half" "" "%{%5%}%N4")
-
-(define_subst "maskz_half"
-  [(set (match_operand:SUBST_V 0)
-        (match_operand:SUBST_V 1))]
-  ""
-  [(set (match_dup 0)
-        (vec_merge:SUBST_V
-	  (match_dup 1)
-	  (match_operand:SUBST_V 2 "const0_operand")
-	  (match_operand:<avx512fmaskhalfmode> 3 "register_operand" "Yk")))])
diff --git a/gcc/testsuite/gcc.target/i386/pr126429-1.c b/gcc/testsuite/gcc.target/i386/pr126429-1.c
new file mode 100644
index 000000000000..ef84fe14d1ca
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr126429-1.c
@@ -0,0 +1,15 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mavx512bf16 -mavx512dq" } */
+/* { dg-final { scan-assembler-not "kmovb" } } */
+
+#include <immintrin.h>
+
+__m512 dp16ps_mask (__m512 src, __mmask16 k, __m512bh a, __m512bh b)
+{
+  return _mm512_mask_dpbf16_ps (src, k, a, b);
+}
+
+__m512 dp16ps_maskz (__mmask16 k, __m512 src, __m512bh a, __m512bh b)
+{
+  return _mm512_maskz_dpbf16_ps (k, src, a, b);
+}