diff options
| author | José Fonseca <jfonseca@vmware.com> | 2010-10-18 09:32:35 -0700 |
|---|---|---|
| committer | José Fonseca <jfonseca@vmware.com> | 2010-10-18 09:32:35 -0700 |
| commit | ac17c62ecebf684eefcff65b9d58947a61ac361b (patch) | |
| tree | fbba96d5ff680c9b9d643ad5b8dc59700f668899 /src/gallium/auxiliary/gallivm/lp_bld_arit.c | |
| parent | 746b602fbdd6e7955e076c0c0d39e86b01bd3dfd (diff) | |
gallivm: Add a note about SSE4.1's nearest mode rounding.
Diffstat (limited to 'src/gallium/auxiliary/gallivm/lp_bld_arit.c')
| -rw-r--r-- | src/gallium/auxiliary/gallivm/lp_bld_arit.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_arit.c b/src/gallium/auxiliary/gallivm/lp_bld_arit.c index 00f419a486..f9a12a41a1 100644 --- a/src/gallium/auxiliary/gallivm/lp_bld_arit.c +++ b/src/gallium/auxiliary/gallivm/lp_bld_arit.c @@ -983,6 +983,12 @@ enum lp_build_round_sse41_mode }; +/** + * Helper for SSE4.1's ROUNDxx instructions. + * + * NOTE: In the SSE4.1's nearest mode, if two values are equally close, the + * result is the even value. That is, rounding 2.5 will be 2.0, and not 3.0. + */ static INLINE LLVMValueRef lp_build_round_sse41(struct lp_build_context *bld, LLVMValueRef a, |