[mips] Remap move as or.
Summary:
This patch remaps the assembly idiom 'move' to 'or' instead of 'daddu' or
'addu'. The use of addu/daddu instead of or as move was highlighted as a
performance issue during the analysis of a recent 64bit design. Originally
move was encoded as 'or' by binutils but was changed for the r10k cpu family
due to their pipeline which had 2 arithmetic units and a single logical unit,
and so could issue multiple (d)addu based moves at the same time but only 1
logical move.
This patch preserves the disassembly behaviour so that disassembling a old style
(d)addu move still appears as move, but assembling move always gives an or
Patch by Simon Dardis.
Reviewers: vkalintiris
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D11796
llvm-svn: 244579
diff --git a/llvm/lib/Target/Mips/MCTargetDesc/MipsABIInfo.cpp b/llvm/lib/Target/Mips/MCTargetDesc/MipsABIInfo.cpp
index 8e6c9e6..14c5a34 100644
--- a/llvm/lib/Target/Mips/MCTargetDesc/MipsABIInfo.cpp
+++ b/llvm/lib/Target/Mips/MCTargetDesc/MipsABIInfo.cpp
@@ -115,6 +115,10 @@
return ArePtrs64bit() ? Mips::DADDiu : Mips::ADDiu;
}
+unsigned MipsABIInfo::GetGPRMoveOp() const {
+ return ArePtrs64bit() ? Mips::OR64 : Mips::OR;
+}
+
unsigned MipsABIInfo::GetEhDataReg(unsigned I) const {
static const unsigned EhDataReg[] = {
Mips::A0, Mips::A1, Mips::A2, Mips::A3