[X86] Replace slow LEA instructions in X86
According to Intel's Optimization Reference Manual for SNB+:
" For LEA instructions with three source operands and some specific situations, instruction latency has increased to 3 cycles, and must
dispatch via port 1:
- LEA that has all three source operands: base, index, and offset
- LEA that uses base and index registers where the base is EBP, RBP,or R13
- LEA that uses RIP relative addressing mode
- LEA that uses 16-bit addressing mode "
This patch currently handles the first 2 cases only.
Differential Revision: https://reviews.llvm.org/D32277
llvm-svn: 303333
diff --git a/llvm/lib/Target/X86/X86TargetMachine.cpp b/llvm/lib/Target/X86/X86TargetMachine.cpp
index 0fd5617..a42aeed 100644
--- a/llvm/lib/Target/X86/X86TargetMachine.cpp
+++ b/llvm/lib/Target/X86/X86TargetMachine.cpp
@@ -61,6 +61,7 @@
namespace llvm {
void initializeWinEHStatePassPass(PassRegistry &);
+void initializeFixupLEAPassPass(PassRegistry &);
void initializeX86ExecutionDepsFixPass(PassRegistry &);
} // end namespace llvm
@@ -75,6 +76,7 @@
initializeWinEHStatePassPass(PR);
initializeFixupBWInstPassPass(PR);
initializeEvexToVexInstPassPass(PR);
+ initializeFixupLEAPassPass(PR);
initializeX86ExecutionDepsFixPass(PR);
}