x86-64: honor REX prefixes for SSE2AVX

Legacy encoded insns do so, and their automatic conversion to AVX ones
ought to produce functionally identical code. Therefore explicit REX
prefixes cannot simply be ignored. This is in particular relevant
because at least PCMPESTR{I,M}'s 64-bit forms couldn't be expressed in
older gas by other than using a REX64 prefix.

diff --git a/gas/ChangeLog b/gas/ChangeLog
index 835a5525d6e8800652efe7f10aa8fd076da6a30e..c2fa02d03caf37586c66809e372f6491ef982ce3 100644 (file)
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,13 @@
+2020-06-25  Jan Beulich  <jbeulich@suse.com>
+
+       * config/tc-i386.c (process_operands): Translate explicit REX
+       prefix into i.rex for SSE2AVX templates.
+       (set_rex_vrex): New helper.
+       (build_modrm_byte): Use it.
+       * testsuite/gas/i386/x86-64-sse2avx.s: Add cases with explict
+       REX prefixes.
+       * testsuite/gas/i386/x86-64-sse2avx.d: Adjust expectations.
+
 2020-06-25  Jan Beulich  <jbeulich@suse.com>
 
        * config/tc-i386.c (cpu_flags_match): Only match SSE2AVX

diff --git a/gas/config/tc-i386.c b/gas/config/tc-i386.c
index 5a652a9b9b333273ec4ec20aad495f165b11c284..c84192e03100431daa0ad3e3e9a8b9fe7bb8ab39 100644 (file)
--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -7408,6 +7408,15 @@ process_operands (void)
      unnecessary segment overrides.  */
   const seg_entry *default_seg = 0;
 
+  if (i.tm.opcode_modifier.sse2avx)
+    {
+      /* Legacy encoded insns allow explicit REX prefixes, so these prefixes
+        need converting.  */
+      i.rex |= i.prefix[REX_PREFIX] & (REX_W | REX_R | REX_X | REX_B);
+      i.prefix[REX_PREFIX] = 0;
+      i.rex_encoding = 0;
+    }
+
   if (i.tm.opcode_modifier.sse2avx && i.tm.opcode_modifier.vexvvvv)
     {
       unsigned int dupl = i.operands;
@@ -7645,6 +7654,25 @@ process_operands (void)
   return 1;
 }
 
+static INLINE void set_rex_vrex (const reg_entry *r, unsigned int rex_bit,
+                                bfd_boolean do_sse2avx)
+{
+  if (r->reg_flags & RegRex)
+    {
+      if (i.rex & rex_bit)
+       as_bad (_("same type of prefix used twice"));
+      i.rex |= rex_bit;
+    }
+  else if (do_sse2avx && (i.rex & rex_bit) && i.vex.register_specifier)
+    {
+      gas_assert (i.vex.register_specifier == r);
+      i.vex.register_specifier += 8;
+    }
+
+  if (r->reg_flags & RegVRex)
+    i.vrex |= rex_bit;
+}
+
 static const seg_entry *
 build_modrm_byte (void)
 {
@@ -7875,27 +7903,15 @@ build_modrm_byte (void)
              else
                i.has_regxmm = TRUE;
            }
-         if ((i.op[dest].regs->reg_flags & RegRex) != 0)
-           i.rex |= REX_R;
-         if ((i.op[dest].regs->reg_flags & RegVRex) != 0)
-           i.vrex |= REX_R;
-         if ((i.op[source].regs->reg_flags & RegRex) != 0)
-           i.rex |= REX_B;
-         if ((i.op[source].regs->reg_flags & RegVRex) != 0)
-           i.vrex |= REX_B;
+         set_rex_vrex (i.op[dest].regs, REX_R, i.tm.opcode_modifier.sse2avx);
+         set_rex_vrex (i.op[source].regs, REX_B, FALSE);
        }
       else
        {
          i.rm.reg = i.op[source].regs->reg_num;
          i.rm.regmem = i.op[dest].regs->reg_num;
-         if ((i.op[dest].regs->reg_flags & RegRex) != 0)
-           i.rex |= REX_B;
-         if ((i.op[dest].regs->reg_flags & RegVRex) != 0)
-           i.vrex |= REX_B;
-         if ((i.op[source].regs->reg_flags & RegRex) != 0)
-           i.rex |= REX_R;
-         if ((i.op[source].regs->reg_flags & RegVRex) != 0)
-           i.vrex |= REX_R;
+         set_rex_vrex (i.op[dest].regs, REX_B, i.tm.opcode_modifier.sse2avx);
+         set_rex_vrex (i.op[source].regs, REX_R, FALSE);
        }
       if (flag_code != CODE_64BIT && (i.rex & REX_R))
        {
@@ -7945,10 +7961,7 @@ build_modrm_byte (void)
                    }
                }
              i.sib.index = i.index_reg->reg_num;
-             if ((i.index_reg->reg_flags & RegRex) != 0)
-               i.rex |= REX_X;
-             if ((i.index_reg->reg_flags & RegVRex) != 0)
-               i.vrex |= REX_X;
+             set_rex_vrex (i.index_reg, REX_X, FALSE);
            }
 
          default_seg = &ds;
@@ -8314,18 +8327,14 @@ build_modrm_byte (void)
              if (i.tm.extension_opcode != None)
                {
                  i.rm.regmem = i.op[op].regs->reg_num;
-                 if ((i.op[op].regs->reg_flags & RegRex) != 0)
-                   i.rex |= REX_B;
-                 if ((i.op[op].regs->reg_flags & RegVRex) != 0)
-                   i.vrex |= REX_B;
+                 set_rex_vrex (i.op[op].regs, REX_B,
+                               i.tm.opcode_modifier.sse2avx);
                }
              else
                {
                  i.rm.reg = i.op[op].regs->reg_num;
-                 if ((i.op[op].regs->reg_flags & RegRex) != 0)
-                   i.rex |= REX_R;
-                 if ((i.op[op].regs->reg_flags & RegVRex) != 0)
-                   i.vrex |= REX_R;
+                 set_rex_vrex (i.op[op].regs, REX_R,
+                               i.tm.opcode_modifier.sse2avx);
                }
            }
 

diff --git a/gas/testsuite/gas/i386/x86-64-sse2avx.d b/gas/testsuite/gas/i386/x86-64-sse2avx.d
index bb9976e3991a23ccebcc010ccb2561ad71849fb9..8eed2db5dd7b206a31c69317ba152bd57564f9af 100644 (file)
--- a/gas/testsuite/gas/i386/x86-64-sse2avx.d
+++ b/gas/testsuite/gas/i386/x86-64-sse2avx.d
@@ -711,6 +711,33 @@ Disassembly of section .text:
 [      ]*[a-f0-9]+:    c5 d9 73 d4 64          vpsrlq \$0x64,%xmm4,%xmm4
 [      ]*[a-f0-9]+:    c5 d9 71 d4 64          vpsrlw \$0x64,%xmm4,%xmm4
 [      ]*[a-f0-9]+:    c5 f9 c5 cc 64          vpextrw \$0x64,%xmm4,%ecx
+[      ]*[a-f0-9]+:    c5 f8 58 c0             vaddps %xmm0,%xmm0,%xmm0
+[      ]*[a-f0-9]+:    c5 f8 58 04 00          vaddps \(%rax,%rax(,1)?\),%xmm0,%xmm0
+[      ]*[a-f0-9]+:    c5 f8 58 c0             vaddps %xmm0,%xmm0,%xmm0
+[      ]*[a-f0-9]+:    c5 f8 58 04 00          vaddps \(%rax,%rax(,1)?\),%xmm0,%xmm0
+[      ]*[a-f0-9]+:    c5 38 58 c0             vaddps %xmm0,%xmm8,%xmm8
+[      ]*[a-f0-9]+:    c5 38 58 04 00          vaddps \(%rax,%rax(,1)?\),%xmm8,%xmm8
+[      ]*[a-f0-9]+:    c4 a1 78 58 c0          vaddps %xmm0,%xmm0,%xmm0
+[      ]*[a-f0-9]+:    c4 a1 78 58 04 00       vaddps \(%rax,%r8(,1)?\),%xmm0,%xmm0
+[      ]*[a-f0-9]+:    c4 c1 78 58 c0          vaddps %xmm8,%xmm0,%xmm0
+[      ]*[a-f0-9]+:    c4 c1 78 58 04 00       vaddps \(%r8,%rax(,1)?\),%xmm0,%xmm0
+[      ]*[a-f0-9]+:    c5 3a 10 c0             vmovss %xmm0,%xmm8,%xmm8
+[      ]*[a-f0-9]+:    c4 c1 7a 10 c0          vmovss %xmm8,%xmm0,%xmm0
+[      ]*[a-f0-9]+:    c5 7a 11 c0             vmovss %xmm8,%xmm0,%xmm0
+[      ]*[a-f0-9]+:    c4 c1 3a 11 c0          vmovss %xmm0,%xmm8,%xmm8
+[      ]*[a-f0-9]+:    c4 c1 39 71 f0 00       vpsllw \$(0x)?0,%xmm8,%xmm8
+[      ]*[a-f0-9]+:    c5 79 c5 c0 00          vpextrw \$(0x)?0,%xmm0,%r8d
+[      ]*[a-f0-9]+:    c4 c1 79 c5 c0 00       vpextrw \$(0x)?0,%xmm8,%eax
+[      ]*[a-f0-9]+:    c4 63 79 14 c0 00       vpextrb \$(0x)?0,%xmm8,%eax
+[      ]*[a-f0-9]+:    c4 c3 79 14 c0 00       vpextrb \$(0x)?0,%xmm0,%r8d
+[      ]*[a-f0-9]+:    c4 63 39 4a c0 00       vblendvps %xmm0,%xmm0,%xmm8,%xmm8
+[      ]*[a-f0-9]+:    c4 c3 79 4a c0 00       vblendvps %xmm0,%xmm8,%xmm0,%xmm0
+[      ]*[a-f0-9]+:    c4 63 39 4a c0 00       vblendvps %xmm0,%xmm0,%xmm8,%xmm8
+[      ]*[a-f0-9]+:    c4 c3 79 4a c0 00       vblendvps %xmm0,%xmm8,%xmm0,%xmm0
+[      ]*[a-f0-9]+:    c4 e1 fb 2a 00          vcvtsi2sdq \(%rax\),%xmm0,%xmm0
+[      ]*[a-f0-9]+:    c4 e1 fa 2a 00          vcvtsi2ssq \(%rax\),%xmm0,%xmm0
+[      ]*[a-f0-9]+:    c4 e3 f9 61 c0 00       vpcmpestriq \$(0x)?0,%xmm0,%xmm0
+[      ]*[a-f0-9]+:    c4 e3 f9 60 c0 00       vpcmpestrmq \$(0x)?0,%xmm0,%xmm0
 [      ]*[a-f0-9]+:    c5 f8 ae 11             vldmxcsr \(%rcx\)
 [      ]*[a-f0-9]+:    c5 f8 ae 19             vstmxcsr \(%rcx\)
 [      ]*[a-f0-9]+:    c5 f8 5b f4             vcvtdq2ps %xmm4,%xmm6

diff --git a/gas/testsuite/gas/i386/x86-64-sse2avx.s b/gas/testsuite/gas/i386/x86-64-sse2avx.s
index 08d1b250f3622abf008927a8f7c1990935b92c2e..1d3cda18152d74543a92c45fad926cc4fb3271aa 100644 (file)
--- a/gas/testsuite/gas/i386/x86-64-sse2avx.s
+++ b/gas/testsuite/gas/i386/x86-64-sse2avx.s
@@ -802,6 +802,44 @@ _start:
 # Tests for op imm8, xmm, regl
        pextrw $100,%xmm4,%ecx
 
+# Tests for REX prefix conversion
+       {rex} addps %xmm0, %xmm0
+       {rex} addps (%rax,%rax), %xmm0
+       rex addps %xmm0, %xmm0
+       rex addps (%rax,%rax), %xmm0
+       rexx addps %xmm0, %xmm0
+       rexx addps (%rax,%rax), %xmm0
+       rexy addps %xmm0, %xmm0
+       rexy addps (%rax,%rax), %xmm0
+       rexz addps %xmm0, %xmm0
+       rexz addps (%rax,%rax), %xmm0
+
+       {load} rexx movss %xmm0, %xmm0
+       {load} rexz movss %xmm0, %xmm0
+
+       {store} rexx movss %xmm0, %xmm0
+       {store} rexz movss %xmm0, %xmm0
+
+       rexz psllw $0, %xmm0
+
+       rexx pextrw $0, %xmm0, %eax
+       rexz pextrw $0, %xmm0, %eax
+
+       rexx pextrb $0, %xmm0, %eax
+       rexz pextrb $0, %xmm0, %eax
+
+       rexx blendvps %xmm0, %xmm0, %xmm0
+       rexz blendvps %xmm0, %xmm0, %xmm0
+
+       rexx blendvps %xmm0, %xmm0
+       rexz blendvps %xmm0, %xmm0
+
+       rex64 cvtsi2sd (%rax), %xmm0
+       rex64 cvtsi2ss (%rax), %xmm0
+
+       rex64 pcmpestri $0, %xmm0, %xmm0
+       rex64 pcmpestrm $0, %xmm0, %xmm0
+
 
        .intel_syntax noprefix
 # Tests for op mem64
@@ -1505,4 +1543,3 @@ _start:
 
 # Tests for op imm8, xmm, regl
        pextrw ecx,xmm4,100
-