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| author | Chris Lattner <sabre@nondot.org> | 2012-09-03 02:58:21 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2012-09-03 02:58:21 +0000 |
| commit | 8a04e51d861032fe9e62612cf3298cd8bc18cc2e (patch) | |
| tree | 8d8a48e0b4050ddaa413e37241697e14f9ac79c2 /lib/Target/X86/README-SSE.txt | |
| parent | 3a86e1396230748f17a521915bc802939a787eac (diff) | |
| download | llvm-8a04e51d861032fe9e62612cf3298cd8bc18cc2e.tar.gz llvm-8a04e51d861032fe9e62612cf3298cd8bc18cc2e.tar.bz2 llvm-8a04e51d861032fe9e62612cf3298cd8bc18cc2e.tar.xz | |
some peepholes that should match horizontal add/sub operations.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163103 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/X86/README-SSE.txt')
| -rw-r--r-- | lib/Target/X86/README-SSE.txt | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/lib/Target/X86/README-SSE.txt b/lib/Target/X86/README-SSE.txt index 624e56fa0f..40110353fc 100644 --- a/lib/Target/X86/README-SSE.txt +++ b/lib/Target/X86/README-SSE.txt @@ -941,3 +941,15 @@ and inversion with an rsqrtss instruction, which computes 1/sqrt faster at the cost of reduced accuracy. //===---------------------------------------------------------------------===// + +This function should be matched to haddpd when the appropriate CPU is enabled: + +#include <x86intrin.h> +double f (__m128d p) { + return p[0] + p[1]; +} + +similarly, v[0]-v[1] should match to hsubpd, and {v[0]-v[1], w[0]-w[1]} should +turn into hsubpd also. + +//===---------------------------------------------------------------------===// |