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| author | Jennifer Schmitz <jschmitz@nvidia.com> | 2024-10-17 08:40:34 -0700 |
|---|---|---|
| committer | Jennifer Schmitz <jschmitz@nvidia.com> | 2024-10-25 15:56:41 +0200 |
| commit | 07a8538d90763f0ae640dea822bdeb63ea17ec44 (patch) | |
| tree | d145b1a67d709f6d2935e6b4eb808444929223b1 /gcc/match.pd | |
| parent | df4af89bc3eabbeaccb16539aa1082cb9863e187 (diff) | |
| download | gcc-07a8538d90763f0ae640dea822bdeb63ea17ec44.zip gcc-07a8538d90763f0ae640dea822bdeb63ea17ec44.tar.gz gcc-07a8538d90763f0ae640dea822bdeb63ea17ec44.tar.bz2 | |
match.pd: Add std::pow folding optimizations.
This patch adds the following two simplifications in match.pd for
POW_ALL and POWI:
- pow (1.0/x, y) to pow (x, -y), avoiding the division
- pow (0.0, x) to 0.0, avoiding the call to pow.
The patterns are guarded by flag_unsafe_math_optimizations,
!flag_trapping_math, and !HONOR_INFINITIES.
The POW_ALL patterns are also gated under !flag_errno_math.
The second pattern is also guarded by !HONOR_NANS and
!HONOR_SIGNED_ZEROS.
Tests were added to confirm the application of the transform for
builtins pow, powf, powl, powi, powif, powil, and powf16.
The patch was bootstrapped and regtested on aarch64-linux-gnu and
x86_64-linux-gnu, no regression.
OK for mainline?
Signed-off-by: Jennifer Schmitz <jschmitz@nvidia.com>
gcc/
* match.pd: Fold pow (1.0/x, y) -> pow (x, -y) and
pow (0.0, x) -> 0.0.
gcc/testsuite/
* gcc.dg/tree-ssa/pow_fold_1.c: New test.
Diffstat (limited to 'gcc/match.pd')
| -rw-r--r-- | gcc/match.pd | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/gcc/match.pd b/gcc/match.pd index f16b733..809c717 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -8285,6 +8285,21 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) (rdiv @0 (exps:s @1)) (mult @0 (exps (negate @1))))) + (for pow (POW_ALL) + (if (! HONOR_INFINITIES (type) + && ! flag_trapping_math + && ! flag_errno_math) + /* Simplify pow(1.0/x, y) into pow(x, -y). */ + (simplify + (pow (rdiv:s real_onep@0 @1) @2) + (pow @1 (negate @2))) + + /* Simplify pow(0.0, x) into 0.0. */ + (if (! HONOR_NANS (type) && ! HONOR_SIGNED_ZEROS (type)) + (simplify + (pow real_zerop@0 @1) + @0)))) + (if (! HONOR_SIGN_DEPENDENT_ROUNDING (type) && ! HONOR_NANS (type) && ! HONOR_INFINITIES (type) && ! flag_trapping_math @@ -8643,6 +8658,19 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) (mult (POW:s @0 @1) (POW:s @2 @1)) (POW (mult @0 @2) @1)) + (if (! HONOR_INFINITIES (type) && ! flag_trapping_math) + /* Simplify powi(1.0/x, y) into powi(x, -y). */ + (simplify + (POWI (rdiv@3 real_onep@0 @1) @2) + (if (single_use (@3)) + (POWI @1 (negate @2)))) + + /* Simplify powi(0.0, x) into 0.0. */ + (if (! HONOR_NANS (type) && ! HONOR_SIGNED_ZEROS (type)) + (simplify + (POWI real_zerop@0 @1) + @0))) + /* Simplify powi(x,y) * powi(z,y) -> powi(x*z,y). */ (simplify (mult (POWI:s @0 @1) (POWI:s @2 @1)) |