add a comment, make save/restore logic more obvious.

llvm-svn: 60076
This commit is contained in:
Chris Lattner 2008-11-26 02:11:11 +00:00
parent eb3e4fb6fb
commit 383a797f42
1 changed files with 7 additions and 7 deletions

View File

@ -864,22 +864,22 @@ bool AddressingModeMatcher::MatchAddr(Value *Addr, unsigned Depth) {
// Worse case, the target should support [reg] addressing modes. :) // Worse case, the target should support [reg] addressing modes. :)
if (!AddrMode.HasBaseReg) { if (!AddrMode.HasBaseReg) {
AddrMode.HasBaseReg = true; AddrMode.HasBaseReg = true;
AddrMode.BaseReg = Addr;
// Still check for legality in case the target supports [imm] but not [i+r]. // Still check for legality in case the target supports [imm] but not [i+r].
if (TLI.isLegalAddressingMode(AddrMode, AccessTy)) { if (TLI.isLegalAddressingMode(AddrMode, AccessTy))
AddrMode.BaseReg = Addr;
return true; return true;
}
AddrMode.HasBaseReg = false; AddrMode.HasBaseReg = false;
AddrMode.BaseReg = 0;
} }
// If the base register is already taken, see if we can do [r+r]. // If the base register is already taken, see if we can do [r+r].
if (AddrMode.Scale == 0) { if (AddrMode.Scale == 0) {
AddrMode.Scale = 1; AddrMode.Scale = 1;
if (TLI.isLegalAddressingMode(AddrMode, AccessTy)) { AddrMode.ScaledReg = Addr;
AddrMode.ScaledReg = Addr; if (TLI.isLegalAddressingMode(AddrMode, AccessTy))
return true; return true;
}
AddrMode.Scale = 0; AddrMode.Scale = 0;
AddrMode.ScaledReg = 0;
} }
// Couldn't match. // Couldn't match.
return false; return false;
@ -954,7 +954,7 @@ cl::opt<bool> ENABLECRAZYHACK("enable-smarter-addr-folding", cl::Hidden);
/// ///
/// Note that this (like most of CodeGenPrepare) is just a rough heuristic. If /// 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 /// 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:: bool AddressingModeMatcher::
IsProfitableToFoldIntoAddressingMode(Instruction *I) { IsProfitableToFoldIntoAddressingMode(Instruction *I) {
if (IgnoreProfitability || !ENABLECRAZYHACK) return true; if (IgnoreProfitability || !ENABLECRAZYHACK) return true;