From 7b22976de3307b8b0305ead5f656b50ea049706c Mon Sep 17 00:00:00 2001 From: Craig Topper Date: Mon, 3 Oct 2011 07:51:09 +0000 Subject: Fix VEX disassembling to ignore REX.RXBW bits in 32-bit mode. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@140993 91177308-0d34-0410-b5e6-96231b3b80d8 --- .../X86/Disassembler/X86DisassemblerDecoder.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) diff --git a/lib/Target/X86/Disassembler/X86DisassemblerDecoder.c b/lib/Target/X86/Disassembler/X86DisassemblerDecoder.c index 8a88955561..1d5ad4c052 100644 --- a/lib/Target/X86/Disassembler/X86DisassemblerDecoder.c +++ b/lib/Target/X86/Disassembler/X86DisassemblerDecoder.c @@ -406,12 +406,14 @@ static int readPrefixes(struct InternalInstruction* insn) { consumeByte(insn, &insn->vexPrefix[2]); /* We simulate the REX prefix for simplicity's sake */ - - insn->rexPrefix = 0x40 - | (wFromVEX3of3(insn->vexPrefix[2]) << 3) - | (rFromVEX2of3(insn->vexPrefix[1]) << 2) - | (xFromVEX2of3(insn->vexPrefix[1]) << 1) - | (bFromVEX2of3(insn->vexPrefix[1]) << 0); + + if (insn->mode == MODE_64BIT) { + insn->rexPrefix = 0x40 + | (wFromVEX3of3(insn->vexPrefix[2]) << 3) + | (rFromVEX2of3(insn->vexPrefix[1]) << 2) + | (xFromVEX2of3(insn->vexPrefix[1]) << 1) + | (bFromVEX2of3(insn->vexPrefix[1]) << 0); + } switch (ppFromVEX3of3(insn->vexPrefix[2])) { @@ -444,8 +446,10 @@ static int readPrefixes(struct InternalInstruction* insn) { insn->vexPrefix[0] = byte; consumeByte(insn, &insn->vexPrefix[1]); - insn->rexPrefix = 0x40 - | (rFromVEX2of2(insn->vexPrefix[1]) << 2); + if (insn->mode == MODE_64BIT) { + insn->rexPrefix = 0x40 + | (rFromVEX2of2(insn->vexPrefix[1]) << 2); + } switch (ppFromVEX2of2(insn->vexPrefix[1])) { @@ -763,7 +767,7 @@ static int getID(struct InternalInstruction* insn) { break; } - if (wFromVEX3of3(insn->vexPrefix[2])) + if (insn->mode == MODE_64BIT && wFromVEX3of3(insn->vexPrefix[2])) attrMask |= ATTR_REXW; if (lFromVEX3of3(insn->vexPrefix[2])) attrMask |= ATTR_VEXL; -- cgit v1.2.3