diff options
author | Chris Lattner <sabre@nondot.org> | 2010-01-13 23:29:11 +0000 |
---|---|---|
committer | Chris Lattner <sabre@nondot.org> | 2010-01-13 23:29:11 +0000 |
commit | 5350f78323924d7f7e27fa0c868b332a91624eee (patch) | |
tree | 52478e845bc0dd3628eb617d180612f77b8715e0 | |
parent | 689339c50f957b21861038e69fc8ee71ecae14b2 (diff) | |
download | llvm-5350f78323924d7f7e27fa0c868b332a91624eee.tar.gz llvm-5350f78323924d7f7e27fa0c868b332a91624eee.tar.bz2 llvm-5350f78323924d7f7e27fa0c868b332a91624eee.tar.xz |
this is an SSE-specific issue.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93373 91177308-0d34-0410-b5e6-96231b3b80d8
-rw-r--r-- | lib/Target/X86/README-SSE.txt | 20 | ||||
-rw-r--r-- | lib/Target/X86/README.txt | 20 |
2 files changed, 20 insertions, 20 deletions
diff --git a/lib/Target/X86/README-SSE.txt b/lib/Target/X86/README-SSE.txt index 71ad51c798..0f3e44b528 100644 --- a/lib/Target/X86/README-SSE.txt +++ b/lib/Target/X86/README-SSE.txt @@ -916,3 +916,23 @@ cheaper to do fld1 than load from a constant pool for example, so "load, add 1.0, store" is better done in the fp stack, etc. //===---------------------------------------------------------------------===// + +The X86 backend should be able to if-convert SSE comparisons like "ucomisd" to +"cmpsd". For example, this code: + +double d1(double x) { return x == x ? x : x + x; } + +Compiles into: + +_d1: + ucomisd %xmm0, %xmm0 + jnp LBB1_2 + addsd %xmm0, %xmm0 + ret +LBB1_2: + ret + +Also, the 'ret's should be shared. This is PR6032. + +//===---------------------------------------------------------------------===// + diff --git a/lib/Target/X86/README.txt b/lib/Target/X86/README.txt index f146ff3634..aa7bb3d978 100644 --- a/lib/Target/X86/README.txt +++ b/lib/Target/X86/README.txt @@ -1868,23 +1868,3 @@ carried over to machine instructions. Asm printer (or JIT) can use this information to add the "lock" prefix. //===---------------------------------------------------------------------===// - -The X86 backend should be able to if-convert SSE comparisons like "ucomisd" to -"cmpsd". For example, this code: - -double d1(double x) { return x == x ? x : x + x; } - -Compiles into: - -_d1: - ucomisd %xmm0, %xmm0 - jnp LBB1_2 - addsd %xmm0, %xmm0 - ret -LBB1_2: - ret - -Also, the 'ret's should be shared. This is PR6032. - -//===---------------------------------------------------------------------===// - |