Fix a bug in the calculation of the VEX.B bit for FMA4 rr with the VEX.W bit set. The VEX.B was being calculated from the wrong operand. Fixes at least some portion of PR14185.
llvm-svn: 177014
diff --git a/llvm/lib/Target/X86/X86CodeEmitter.cpp b/llvm/lib/Target/X86/X86CodeEmitter.cpp
index ece38aa..a6bb2a7 100644
--- a/llvm/lib/Target/X86/X86CodeEmitter.cpp
+++ b/llvm/lib/Target/X86/X86CodeEmitter.cpp
@@ -816,6 +816,7 @@
const MCInstrDesc *Desc) const {
bool HasVEX_4V = (TSFlags >> X86II::VEXShift) & X86II::VEX_4V;
bool HasVEX_4VOp3 = (TSFlags >> X86II::VEXShift) & X86II::VEX_4VOp3;
+ bool HasMemOp4 = (TSFlags >> X86II::VEXShift) & X86II::MemOp4;
// VEX_R: opcode externsion equivalent to REX.R in
// 1's complement (inverted) form
@@ -1032,6 +1033,10 @@
if (HasVEX_4V)
VEX_4V = getVEXRegisterEncoding(MI, CurOp++);
+
+ if (MemOp4) // Skip second register source (encoded in I8IMM)
+ CurOp++;
+
if (X86II::isX86_64ExtendedReg(MI.getOperand(CurOp).getReg()))
VEX_B = 0x0;
CurOp++;