6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-08-17 21:29:20 +00:00
Code Issues Projects Releases Wiki Activity

X86 codegen tweak to use lea in another case:

Browse Source 
Suppose base == %eax and it has multiple uses, then instead of
  movl %eax, %ecx
  addl $8, %ecx
use
  leal 8(%eax), %ecx.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26323 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng 2006-02-23 00:13:58 +00:00
parent 4ba9cd53ba
commit 224ec39cab
1 changed files with 12 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
lib/Target/X86/X86ISelDAGToDAG.cpp
View File

@ -457,23 +457,19 @@ bool X86DAGToDAGISel::SelectLEAAddr(SDOperand N, SDOperand &Base,
SDOperand &Index, SDOperand &Disp) {
X86ISelAddressMode AM;
if (!MatchAddress(N, AM)) {
bool SelectBase = false;
bool SelectIndex = false;
bool Check = false;
if (AM.BaseType == X86ISelAddressMode::RegBase) {
if (AM.Base.Reg.Val) {
Check = true;
SelectBase = true;
} else {
if (AM.Base.Reg.Val)
Check = true;
else
AM.Base.Reg = CurDAG->getRegister(0, MVT::i32);
}
}
if (AM.IndexReg.Val) {
if (AM.IndexReg.Val)
SelectIndex = true;
} else {
else
AM.IndexReg = CurDAG->getRegister(0, MVT::i32);
}
if (Check) {
unsigned Complexity = 0;
@ -485,6 +481,13 @@ bool X86DAGToDAGISel::SelectLEAAddr(SDOperand N, SDOperand &Base,
Complexity++;
else if (AM.Disp > 1)
Complexity++;
// Suppose base == %eax and it has multiple uses, then instead of
// movl %eax, %ecx
// addl $8, %ecx
// use
// leal 8(%eax), %ecx.
if (AM.Base.Reg.Val->use_size() > 1)
Complexity++;
if (Complexity <= 1)
return false;
}