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| author | Chris Lattner <sabre@nondot.org> | 2007-10-03 03:40:24 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2007-10-03 03:40:24 +0000 |
| commit | 21ba176c4b812c0a83f58b143f33cce2d8d6cfd4 (patch) | |
| tree | 9f73059d4f05657972a1af1adc19a5a3c5f4ab0f /llvm/lib | |
| parent | b60f254975a387d58d2d173531c5a9d844c82c47 (diff) | |
| download | bcm5719-llvm-21ba176c4b812c0a83f58b143f33cce2d8d6cfd4.tar.gz bcm5719-llvm-21ba176c4b812c0a83f58b143f33cce2d8d6cfd4.zip | |
Bill's example is still not enough to repro this, but it has other issues that
seem significant as well.
llvm-svn: 42564
Diffstat (limited to 'llvm/lib')
| -rw-r--r-- | llvm/lib/Target/X86/README.txt | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/llvm/lib/Target/X86/README.txt b/llvm/lib/Target/X86/README.txt index 0fd79f23611..39c8a02e313 100644 --- a/llvm/lib/Target/X86/README.txt +++ b/llvm/lib/Target/X86/README.txt @@ -1277,6 +1277,14 @@ LBB3_5: # bb114.preheader movl %eax, -96(%ebp) movw $0, -98(%ebp) +This appears to be bad because the RA is not folding the store to the stack +slot into the movl. The above instructions could be: + movl $32, -80(%ebp) +... + movl $32, -84(%ebp) +... +This seems like a cross between remat and spill folding. + This has redundant subtractions of %eax from a stack slot. However, %ecx doesn't change, so we could simply subtract %eax from %ecx first and then use %ecx (or vice-versa). |
