Fix PR10677. Initial patch and idea by Peter Cooper but I've changed the

implementation!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@138029 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp b/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp
index cf582b58446a69ca2ed817ff3c56f4f0a9383b7c..6c7b386f2d107eb294fbad8739515f6a75178291 100644 (file)
--- a/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp
+++ b/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp
@@ -533,9 +533,14 @@ void X86MCCodeEmitter::EmitVEXOpcodePrefix(uint64_t TSFlags, unsigned &CurByte,
       const MCOperand &MO = MI.getOperand(CurOp);
       if (MO.isReg() && X86II::isX86_64ExtendedReg(MO.getReg()))
         VEX_B = 0x0;
-      if (!VEX_B && MO.isReg() &&
-          ((TSFlags & X86II::FormMask) == X86II::MRMSrcMem) &&
-          X86II::isX86_64ExtendedReg(MO.getReg()))
+      // Only set VEX_X if the Index Register is extended
+      if (VEX_B || !MO.isReg())
+        continue;
+      if (!X86II::isX86_64ExtendedReg(MO.getReg()))
+        continue;
+      unsigned Frm = TSFlags & X86II::FormMask;
+      if ((Frm == X86II::MRMSrcMem && CurOp-1 == X86::AddrIndexReg) ||
+          (Frm == X86II::MRMDestMem && CurOp == X86::AddrIndexReg))
         VEX_X = 0x0;
     }
     break;

diff --git a/test/MC/X86/x86_64-avx-encoding.s b/test/MC/X86/x86_64-avx-encoding.s
index 7a96bb5a2b4850870b11f8609e7771b763675ecc..590a511280d23684605ac8c28053728650705bd2 100644 (file)
--- a/test/MC/X86/x86_64-avx-encoding.s
+++ b/test/MC/X86/x86_64-avx-encoding.s
@@ -3316,3 +3316,19 @@ vdivpd  -4(%rcx,%rbx,8), %xmm10, %xmm11
 // CHECK: encoding: [0xc4,0x63,0x1d,0x4b,0xac,0x20,0xad,0xde,0x00,0x00,0xb0]
           vblendvpd  %ymm11, 0xdead(%rax,%riz), %ymm12, %ymm13
 
+// CHECK: vmovaps      %xmm3, (%r14,%r11)
+// CHECK: encoding: [0xc4,0x81,0x78,0x29,0x1c,0x1e]
+          vmovaps      %xmm3, (%r14,%r11)
+
+// CHECK: vmovaps      (%r14,%r11), %xmm3
+// CHECK: encoding: [0xc4,0x81,0x78,0x28,0x1c,0x1e]
+          vmovaps      (%r14,%r11), %xmm3
+
+// CHECK: vmovaps      %xmm3, (%r14,%rbx)
+// CHECK: encoding: [0xc4,0xc1,0x78,0x29,0x1c,0x1e]
+          vmovaps      %xmm3, (%r14,%rbx)
+
+// CHECK: vmovaps      (%r14,%rbx), %xmm3
+// CHECK: encoding: [0xc4,0xc1,0x78,0x28,0x1c,0x1e]
+          vmovaps      (%r14,%rbx), %xmm3
+