[X86] Stop printing moves between VR64 and GR64 with 'movd' mnemonic. Use 'movq' instead.

This behavior existed to work with an old version of the gnu assembler on MacOS that only accepted this form. Newer versions of GNU assembler and the current LLVM derived version of the assembler on MacOS support movq as well.

llvm-svn: 321898

2 files changed, 9 insertions, 7 deletions

diff --git a/llvm/lib/Target/X86/X86InstrInfo.td b/llvm/lib/Target/X86/X86InstrInfo.td
index 27c67500b26..ced12be388b 100644
--- a/llvm/lib/Target/X86/X86InstrInfo.td
+++ b/llvm/lib/Target/X86/X86InstrInfo.td
@@ -3208,10 +3208,12 @@ def : InstAlias<"mov\t{$seg, $mem|$mem, $seg}", (MOV16ms i16mem:$mem, SEGMENT_RE
 // Match 'movq <largeimm>, <reg>' as an alias for movabsq.
 def : InstAlias<"mov{q}\t{$imm, $reg|$reg, $imm}", (MOV64ri GR64:$reg, i64imm:$imm), 0>;
 
-// Match 'movq GR64, MMX' as an alias for movd.
-def : InstAlias<"movq\t{$src, $dst|$dst, $src}",
+// Match 'movd GR64, MMX' as an alias for movq to be compatible with gas,
+// which supports this due to an old AMD documentation bug when 64-bit mode was
+// created.
+def : InstAlias<"movd\t{$src, $dst|$dst, $src}",
                 (MMX_MOVD64to64rr VR64:$dst, GR64:$src), 0>;
-def : InstAlias<"movq\t{$src, $dst|$dst, $src}",
+def : InstAlias<"movd\t{$src, $dst|$dst, $src}",
                 (MMX_MOVD64from64rr GR64:$dst, VR64:$src), 0>;
 
 // movsx aliases
diff --git a/llvm/lib/Target/X86/X86InstrMMX.td b/llvm/lib/Target/X86/X86InstrMMX.td
index a481644efdd..18be0a54483 100644
--- a/llvm/lib/Target/X86/X86InstrMMX.td
+++ b/llvm/lib/Target/X86/X86InstrMMX.td
@@ -254,13 +254,13 @@ def MMX_MOVD64grr : MMXI<0x7E, MRMDestReg, (outs GR32:$dst), (ins VR64:$src),
 
 let isBitcast = 1 in
 def MMX_MOVD64to64rr : MMXRI<0x6E, MRMSrcReg, (outs VR64:$dst), (ins GR64:$src),
-                             "movd\t{$src, $dst|$dst, $src}",
+                             "movq\t{$src, $dst|$dst, $src}",
                              [(set VR64:$dst, (bitconvert GR64:$src))],
                              IIC_MMX_MOV_MM_RM>, Sched<[WriteMove]>;
 
 let isCodeGenOnly = 1, ForceDisassemble = 1, hasSideEffects = 0, mayLoad = 1 in
 def MMX_MOVD64to64rm : MMXRI<0x6E, MRMSrcMem, (outs VR64:$dst),
-                             (ins i64mem:$src), "movd\t{$src, $dst|$dst, $src}",
+                             (ins i64mem:$src), "movq\t{$src, $dst|$dst, $src}",
                              [], IIC_MMX_MOVQ_RM>, Sched<[WriteLoad]>;
 
 // These are 64 bit moves, but since the OS X assembler doesn't
@@ -269,7 +269,7 @@ def MMX_MOVD64to64rm : MMXRI<0x6E, MRMSrcMem, (outs VR64:$dst),
 let SchedRW = [WriteMove], isBitcast = 1 in {
 def MMX_MOVD64from64rr : MMXRI<0x7E, MRMDestReg,
                                (outs GR64:$dst), (ins VR64:$src),
-                               "movd\t{$src, $dst|$dst, $src}",
+                               "movq\t{$src, $dst|$dst, $src}",
                              [(set GR64:$dst,
                               (bitconvert VR64:$src))], IIC_MMX_MOV_REG_MM>;
 let hasSideEffects = 0 in
@@ -286,7 +286,7 @@ def MMX_MOVQ64rr_REV : MMXI<0x7F, MRMDestReg, (outs VR64:$dst), (ins VR64:$src),
 let isCodeGenOnly = 1, ForceDisassemble = 1, hasSideEffects = 0, mayStore = 1 in
 def MMX_MOVD64from64rm : MMXRI<0x7E, MRMDestMem,
                                (outs), (ins i64mem:$dst, VR64:$src),
-                               "movd\t{$src, $dst|$dst, $src}",
+                               "movq\t{$src, $dst|$dst, $src}",
                                [], IIC_MMX_MOV_REG_MM>, Sched<[WriteStore]>;
 
 let SchedRW = [WriteLoad] in {