From: Simon Pilgrim <llvm-dev@redking.me.uk>
Date: Sat, 9 Dec 2017 16:58:34 +0000 (+0000)
Subject: [X86] Tag segment prefixes as NOP instruction scheduling classes
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=e0380a51b7f27dbc97457d279f257893b0a6db00;p=llvm

[X86] Tag segment prefixes as NOP instruction scheduling classes

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@320257 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Target/X86/X86InstrSystem.td b/lib/Target/X86/X86InstrSystem.td
index e9739f08147..0c2c78e30a0 100644
--- a/lib/Target/X86/X86InstrSystem.td
+++ b/lib/Target/X86/X86InstrSystem.td
@@ -154,13 +154,14 @@ def MOV64cr : I<0x22, MRMSrcReg, (outs CONTROL_REG:$dst), (ins GR64:$src),
 //===----------------------------------------------------------------------===//
 // Segment override instruction prefixes
 
-def CS_PREFIX : I<0x2E, RawFrm, (outs), (ins), "cs", []>;
-def SS_PREFIX : I<0x36, RawFrm, (outs), (ins), "ss", []>;
-def DS_PREFIX : I<0x3E, RawFrm, (outs), (ins), "ds", []>;
-def ES_PREFIX : I<0x26, RawFrm, (outs), (ins), "es", []>;
-def FS_PREFIX : I<0x64, RawFrm, (outs), (ins), "fs", []>;
-def GS_PREFIX : I<0x65, RawFrm, (outs), (ins), "gs", []>;
-
+let SchedRW = [WriteNop] in {
+def CS_PREFIX : I<0x2E, RawFrm, (outs), (ins), "cs", [], IIC_NOP>;
+def SS_PREFIX : I<0x36, RawFrm, (outs), (ins), "ss", [], IIC_NOP>;
+def DS_PREFIX : I<0x3E, RawFrm, (outs), (ins), "ds", [], IIC_NOP>;
+def ES_PREFIX : I<0x26, RawFrm, (outs), (ins), "es", [], IIC_NOP>;
+def FS_PREFIX : I<0x64, RawFrm, (outs), (ins), "fs", [], IIC_NOP>;
+def GS_PREFIX : I<0x65, RawFrm, (outs), (ins), "gs", [], IIC_NOP>;
+} // SchedRW
 
 //===----------------------------------------------------------------------===//
 // Moves to and from segment registers.