diff options
| author | Bill Wendling <isanbard@gmail.com> | 2007-10-02 21:49:31 +0000 |
|---|---|---|
| committer | Bill Wendling <isanbard@gmail.com> | 2007-10-02 21:49:31 +0000 |
| commit | 7687bd0b2bbff184586f0b4058b93d013a1ce508 (patch) | |
| tree | e51982c645925fe502f3198e3b1960c7310e5864 /lib | |
| parent | 2bb6d459e6efa4a5b36283ac02c9a8c388df3338 (diff) | |
| download | external_llvm-7687bd0b2bbff184586f0b4058b93d013a1ce508.zip external_llvm-7687bd0b2bbff184586f0b4058b93d013a1ce508.tar.gz external_llvm-7687bd0b2bbff184586f0b4058b93d013a1ce508.tar.bz2 | |
Another micro-opt.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@42554 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Target/X86/README.txt | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/lib/Target/X86/README.txt b/lib/Target/X86/README.txt index 81e9797..0fd79f2 100644 --- a/lib/Target/X86/README.txt +++ b/lib/Target/X86/README.txt @@ -1306,3 +1306,19 @@ However, ICC caches this information before the loop and produces this: movl 88(%esp), %eax #481.12 //===---------------------------------------------------------------------===// + +This code: + + %tmp659 = icmp slt i16 %tmp654, 0 ; <i1> [#uses=1] + br i1 %tmp659, label %cond_true662, label %cond_next715 + +produces this: + + testw %cx, %cx + movswl %cx, %esi + jns LBB4_109 # cond_next715 + +Shark tells us that using %cx in the testw instruction is sub-optimal. It +suggests using the 32-bit register (which is what ICC uses). + +//===---------------------------------------------------------------------===// |