diff options
| author | Kenneth Graunke <[email protected]> | 2016-01-27 15:31:53 -0800 |
|---|---|---|
| committer | Kenneth Graunke <[email protected]> | 2016-01-27 15:34:50 -0800 |
| commit | 32e4c5ae30240c6759257ef68e80055f4cf8d612 (patch) | |
| tree | 64734113e009dc48bd857ae42902b60fb6a2e61f /src/glsl/nir | |
| parent | 8f0ef9bbeb2932209f4bdc408f79c2313bd6ba51 (diff) | |
vtn: Make tanh implementation even stupider
The dEQP "precision" test tries to verify that the reference functions
float sinh(float a) { return ((exp(a) - exp(-a)) / 2); }
float cosh(float a) { return ((exp(a) + exp(-a)) / 2); }
float tanh(float a) { return (sinh(a) / cosh(a)); }
produce the same values as the built-ins. We simplified away the
multiplication by 0.5 in the numerator and denominator, and apparently
this causes them not to match for exactly 1 out of 13,632 values.
So, put it back in, fixing the test, but making our code generation
(and precision?) worse.
Diffstat (limited to 'src/glsl/nir')
| -rw-r--r-- | src/glsl/nir/spirv/vtn_glsl450.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/src/glsl/nir/spirv/vtn_glsl450.c b/src/glsl/nir/spirv/vtn_glsl450.c index 8d730168c08..219a9c7dc5f 100644 --- a/src/glsl/nir/spirv/vtn_glsl450.c +++ b/src/glsl/nir/spirv/vtn_glsl450.c @@ -545,12 +545,14 @@ handle_glsl450_alu(struct vtn_builder *b, enum GLSLstd450 entrypoint, return; case GLSLstd450Tanh: - /* (e^x - e^(-x)) / (e^x + e^(-x)) */ + /* (0.5 * (e^x - e^(-x))) / (0.5 * (e^x + e^(-x))) */ val->ssa->def = - nir_fdiv(nb, nir_fsub(nb, build_exp(nb, src[0]), - build_exp(nb, nir_fneg(nb, src[0]))), - nir_fadd(nb, build_exp(nb, src[0]), - build_exp(nb, nir_fneg(nb, src[0])))); + nir_fdiv(nb, nir_fmul(nb, nir_imm_float(nb, 0.5f), + nir_fsub(nb, build_exp(nb, src[0]), + build_exp(nb, nir_fneg(nb, src[0])))), + nir_fmul(nb, nir_imm_float(nb, 0.5f), + nir_fadd(nb, build_exp(nb, src[0]), + build_exp(nb, nir_fneg(nb, src[0]))))); return; case GLSLstd450Asinh: |