add a comment, make save/restore logic more obvious.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60076 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/CodeGenPrepare.cpp b/lib/Transforms/Scalar/CodeGenPrepare.cpp
index 99dba6d..86168e8 100644
--- a/lib/Transforms/Scalar/CodeGenPrepare.cpp
+++ b/lib/Transforms/Scalar/CodeGenPrepare.cpp
@@ -864,22 +864,22 @@
// Worse case, the target should support [reg] addressing modes. :)
if (!AddrMode.HasBaseReg) {
AddrMode.HasBaseReg = true;
+ AddrMode.BaseReg = Addr;
// Still check for legality in case the target supports [imm] but not [i+r].
- if (TLI.isLegalAddressingMode(AddrMode, AccessTy)) {
- AddrMode.BaseReg = Addr;
+ if (TLI.isLegalAddressingMode(AddrMode, AccessTy))
return true;
- }
AddrMode.HasBaseReg = false;
+ AddrMode.BaseReg = 0;
}
// If the base register is already taken, see if we can do [r+r].
if (AddrMode.Scale == 0) {
AddrMode.Scale = 1;
- if (TLI.isLegalAddressingMode(AddrMode, AccessTy)) {
- AddrMode.ScaledReg = Addr;
+ AddrMode.ScaledReg = Addr;
+ if (TLI.isLegalAddressingMode(AddrMode, AccessTy))
return true;
- }
AddrMode.Scale = 0;
+ AddrMode.ScaledReg = 0;
}
// Couldn't match.
return false;
@@ -954,7 +954,7 @@
///
/// Note that this (like most of CodeGenPrepare) is just a rough heuristic. If
/// X was live across 'load Z' for other reasons, we actually *would* want to
-/// fold the addressing mode in the Z case.
+/// fold the addressing mode in the Z case. This would make Y die earlier.
bool AddressingModeMatcher::
IsProfitableToFoldIntoAddressingMode(Instruction *I) {
if (IgnoreProfitability || !ENABLECRAZYHACK) return true;