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| author | Michel Danzer <michel.daenzer@amd.com> | 2014-02-04 07:12:38 +0000 |
|---|---|---|
| committer | Michel Danzer <michel.daenzer@amd.com> | 2014-02-04 07:12:38 +0000 |
| commit | de2e0bc3668ac0e2e64bbef329766fa8119c3204 (patch) | |
| tree | 5ff313f176186d14af9205c6e3786d1aac78c1d5 /lib | |
| parent | e2d1c6c19d8f643edffca86e2944f1aba4c9feea (diff) | |
| download | llvm-de2e0bc3668ac0e2e64bbef329766fa8119c3204.tar.gz llvm-de2e0bc3668ac0e2e64bbef329766fa8119c3204.tar.bz2 llvm-de2e0bc3668ac0e2e64bbef329766fa8119c3204.tar.xz | |
R600/SI: Fix fneg for 0.0
V_ADD_F32 with source modifier does not produce -0.0 for this. Just
manipulate the sign bit directly instead.
Also add a pattern for (fneg (fabs ...)).
Fixes a bunch of bit encoding piglit tests with radeonsi.
Reviewed-by: Tom Stellard <thomas.stellard@amd.com>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200743 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Target/R600/SIInstructions.td | 22 |
1 files changed, 18 insertions, 4 deletions
diff --git a/lib/Target/R600/SIInstructions.td b/lib/Target/R600/SIInstructions.td index a5a0dbb711..ba77e6d9ac 100644 --- a/lib/Target/R600/SIInstructions.td +++ b/lib/Target/R600/SIInstructions.td @@ -1688,16 +1688,30 @@ def : Pat < 0 /* ABS */, 1 /* CLAMP */, 0 /* OMOD */, 0 /* NEG */) >; +/********** ================================ **********/ +/********** Floating point absolute/negative **********/ +/********** ================================ **********/ + +// Manipulate the sign bit directly, as e.g. using the source negation modifier +// in V_ADD_F32_e64 $src, 0, [...] does not result in -0.0 for $src == +0.0, +// breaking the piglit *s-floatBitsToInt-neg* tests + +// TODO: Look into not implementing isFNegFree/isFAbsFree for SI, and possibly +// removing these patterns + +def : Pat < + (fneg (fabs f32:$src)), + (V_OR_B32_e32 $src, (V_MOV_B32_e32 0x80000000)) /* Set sign bit */ +>; + def : Pat < (fabs f32:$src), - (V_ADD_F32_e64 $src, (i32 0 /* SRC1 */), - 1 /* ABS */, 0 /* CLAMP */, 0 /* OMOD */, 0 /* NEG */) + (V_AND_B32_e32 $src, (V_MOV_B32_e32 0x7fffffff)) /* Clear sign bit */ >; def : Pat < (fneg f32:$src), - (V_ADD_F32_e64 $src, (i32 0 /* SRC1 */), - 0 /* ABS */, 0 /* CLAMP */, 0 /* OMOD */, 1 /* NEG */) + (V_XOR_B32_e32 $src, (V_MOV_B32_e32 0x80000000)) /* Toggle sign bit */ >; /********** ================== **********/ |