[gcc r14-2009] x86: make VPTERNLOG* usable on less than 512-bit operands with just AVX512F

[gcc r14-2009] x86: make VPTERNLOG* usable on less than 512-bit operands with just AVX512F

[Jan Beulich]

https://gcc.gnu.org/g:864c6471bdc6cdec6da60b66ac13e9fe3cd73fb8

commit r14-2009-g864c6471bdc6cdec6da60b66ac13e9fe3cd73fb8
Author: Jan Beulich <jbeulich@suse.com>
Date:   Wed Jun 21 08:03:05 2023 +0200

    x86: make VPTERNLOG* usable on less than 512-bit operands with just AVX512F
    
    There's no reason to constrain this to AVX512VL, unless instructed so by
    -mprefer-vector-width=, as the wider operation is unusable for more
    narrow operands only when the possible memory source is a non-broadcast
    one. This way even the scalar copysign<mode>3 can benefit from the
    operation being a single-insn one (leaving aside moves which the
    compiler decides to insert for unclear reasons, and leaving aside the
    fact that bcst_mem_operand() is too restrictive for broadcast to be
    embedded right into VPTERNLOG*).
    
    While there also bring *<avx512>_vternlog<mode>_all's in sync with that
    of the three splitters.
    
    Along with this also request value duplication in
    ix86_expand_copysign()'s call to ix86_build_signbit_mask(), eliminating
    excess space allocation in .rodata.*, filled with zeros which are never
    read.
    
    gcc/
    
            * config/i386/i386-expand.cc (ix86_expand_copysign): Request
            value duplication by ix86_build_signbit_mask() when AVX512F and
            not HFmode.
            * config/i386/sse.md (*<avx512>_vternlog<mode>_all): Convert to
            2-alternative form. Adjust "mode" attribute. Add "enabled"
            attribute.
            (*<avx512>_vpternlog<mode>_1): Also permit when TARGET_AVX512F
            && !TARGET_PREFER_AVX256.
            (*<avx512>_vpternlog<mode>_2): Likewise.
            (*<avx512>_vpternlog<mode>_3): Likewise.
    
    gcc/testsuite/
    
            * gcc.target/i386/avx512f-copysign.c: New test.

Diff:
---
 gcc/config/i386/i386-expand.cc                   |  2 +-
 gcc/config/i386/sse.md                           | 36 +++++++++++++++++-------
 gcc/testsuite/gcc.target/i386/avx512f-copysign.c | 32 +++++++++++++++++++++
 3 files changed, 59 insertions(+), 11 deletions(-)

diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc
index ad2cd079fcb..7bb4d3912a9 100644
--- a/gcc/config/i386/i386-expand.cc
+++ b/gcc/config/i386/i386-expand.cc
@@ -2278,7 +2278,7 @@ ix86_expand_copysign (rtx operands[])
   else
     dest = NULL_RTX;
   op1 = lowpart_subreg (vmode, force_reg (mode, operands[2]), mode);
-  mask = ix86_build_signbit_mask (vmode, 0, 0);
+  mask = ix86_build_signbit_mask (vmode, TARGET_AVX512F && mode != HFmode, 0);
 
   if (CONST_DOUBLE_P (operands[1]))
     {
diff --git a/gcc/config/i386/sse.md b/gcc/config/i386/sse.md
index b99becba516..f793258b6c2 100644
--- a/gcc/config/i386/sse.md
+++ b/gcc/config/i386/sse.md
@@ -12597,22 +12597,35 @@
    (set_attr "mode" "<sseinsnmode>")])
 
 (define_insn "*<avx512>_vternlog<mode>_all"
-  [(set (match_operand:V 0 "register_operand" "=v")
+  [(set (match_operand:V 0 "register_operand" "=v,v")
 	(unspec:V
-	  [(match_operand:V 1 "register_operand" "0")
-	   (match_operand:V 2 "register_operand" "v")
-	   (match_operand:V 3 "bcst_vector_operand" "vmBr")
+	  [(match_operand:V 1 "register_operand" "0,0")
+	   (match_operand:V 2 "register_operand" "v,v")
+	   (match_operand:V 3 "bcst_vector_operand" "vBr,m")
 	   (match_operand:SI 4 "const_0_to_255_operand")]
 	  UNSPEC_VTERNLOG))]
-  "TARGET_AVX512F
+  "(<MODE_SIZE> == 64 || TARGET_AVX512VL
+    || (TARGET_AVX512F && !TARGET_PREFER_AVX256))
 /* Disallow embeded broadcast for vector HFmode since
    it's not real AVX512FP16 instruction.  */
   && (GET_MODE_SIZE (GET_MODE_INNER (<MODE>mode)) >= 4
      || GET_CODE (operands[3]) != VEC_DUPLICATE)"
-  "vpternlog<ternlogsuffix>\t{%4, %3, %2, %0|%0, %2, %3, %4}"
+{
+  if (TARGET_AVX512VL)
+    return "vpternlog<ternlogsuffix>\t{%4, %3, %2, %0|%0, %2, %3, %4}";
+  else
+    return "vpternlog<ternlogsuffix>\t{%4, %g3, %g2, %g0|%g0, %g2, %g3, %4}";
+}
   [(set_attr "type" "sselog")
    (set_attr "prefix" "evex")
-   (set_attr "mode" "<sseinsnmode>")])
+   (set (attr "mode")
+        (if_then_else (match_test "TARGET_AVX512VL")
+		      (const_string "<sseinsnmode>")
+		      (const_string "XI")))
+   (set (attr "enabled")
+	(if_then_else (eq_attr "alternative" "1")
+		      (symbol_ref "<MODE_SIZE> == 64 || TARGET_AVX512VL")
+		      (const_string "*")))])
 
 ;; There must be lots of other combinations like
 ;;
@@ -12641,7 +12654,8 @@
 	  (any_logic2:V
 	    (match_operand:V 3 "regmem_or_bitnot_regmem_operand")
 	    (match_operand:V 4 "regmem_or_bitnot_regmem_operand"))))]
-  "(<MODE_SIZE> == 64 || TARGET_AVX512VL)
+  "(<MODE_SIZE> == 64 || TARGET_AVX512VL
+    || (TARGET_AVX512F && !TARGET_PREFER_AVX256))
    && ix86_pre_reload_split ()
    && (rtx_equal_p (STRIP_UNARY (operands[1]),
 		    STRIP_UNARY (operands[4]))
@@ -12725,7 +12739,8 @@
 	      (match_operand:V 2 "regmem_or_bitnot_regmem_operand"))
 	    (match_operand:V 3 "regmem_or_bitnot_regmem_operand"))
 	  (match_operand:V 4 "regmem_or_bitnot_regmem_operand")))]
-  "(<MODE_SIZE> == 64 || TARGET_AVX512VL)
+  "(<MODE_SIZE> == 64 || TARGET_AVX512VL
+    || (TARGET_AVX512F && !TARGET_PREFER_AVX256))
    && ix86_pre_reload_split ()
    && (rtx_equal_p (STRIP_UNARY (operands[1]),
 		    STRIP_UNARY (operands[4]))
@@ -12808,7 +12823,8 @@
 	    (match_operand:V 1 "regmem_or_bitnot_regmem_operand")
 	    (match_operand:V 2 "regmem_or_bitnot_regmem_operand"))
 	  (match_operand:V 3 "regmem_or_bitnot_regmem_operand")))]
-  "(<MODE_SIZE> == 64 || TARGET_AVX512VL)
+  "(<MODE_SIZE> == 64 || TARGET_AVX512VL
+    || (TARGET_AVX512F && !TARGET_PREFER_AVX256))
    && ix86_pre_reload_split ()"
   "#"
   "&& 1"
diff --git a/gcc/testsuite/gcc.target/i386/avx512f-copysign.c b/gcc/testsuite/gcc.target/i386/avx512f-copysign.c
new file mode 100644
index 00000000000..51ca0284e6c
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/avx512f-copysign.c
@@ -0,0 +1,32 @@
+/* { dg-do compile } */
+/* { dg-options "-mavx512f -mno-avx512vl -mprefer-vector-width=512 -O2" } */
+/* { dg-final { scan-assembler-times "vpternlog\[dq\]\[ \\t\]+\\\$(?:216|228|0xd8|0xe4)," 5 } } */
+
+double cs_df (double x, double y)
+{
+  return __builtin_copysign (x, y);
+}
+
+float cs_sf (float x, float y)
+{
+  return __builtin_copysignf (x, y);
+}
+
+typedef double __attribute__ ((vector_size (16))) v2df;
+typedef double __attribute__ ((vector_size (32))) v4df;
+typedef double __attribute__ ((vector_size (64))) v8df;
+
+v2df cs_v2df (v2df x, v2df y)
+{
+  return __builtin_ia32_copysignpd (x, y);
+}
+
+v4df cs_v4df (v4df x, v4df y)
+{
+  return __builtin_ia32_copysignpd256 (x, y);
+}
+
+v8df cs_v8df (v8df x, v8df y)
+{
+  return __builtin_ia32_copysignpd512 (x, y);
+}