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| author | Richard Guenther <rguenther@suse.de> | 2009-08-18 13:40:18 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2009-08-18 13:40:18 +0000 |
| commit | 776e7174167360fdf2ba990e7c7c22536fe9227a (patch) | |
| tree | 352c74ccff21f703c3493cc20f89542a38b26f32 /gcc/builtins.c | |
| parent | f3252b3c18e688f43df708d0003f0b6e0f89cc17 (diff) | |
| download | gcc-776e7174167360fdf2ba990e7c7c22536fe9227a.zip gcc-776e7174167360fdf2ba990e7c7c22536fe9227a.tar.gz gcc-776e7174167360fdf2ba990e7c7c22536fe9227a.tar.bz2 | |
re PR middle-end/41094 (Erroneous optimization of pow() with -ffast-math)
2009-08-18 Richard Guenther <rguenther@suse.de>
PR middle-end/41094
* builtins.c (fold_builtin_pow): Fold pow(pow(x,y),z) to
pow(x,y*z) only if x is nonnegative.
* gcc.dg/torture/pr41094.c: New testcase.
* gcc.dg/torture/builtin-power-1.c: Adjust.
* gcc.dg/builtins-10.c: Likewise.
From-SVN: r150874
Diffstat (limited to 'gcc/builtins.c')
| -rw-r--r-- | gcc/builtins.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/gcc/builtins.c b/gcc/builtins.c index 025c169..1a9e966 100644 --- a/gcc/builtins.c +++ b/gcc/builtins.c @@ -8737,15 +8737,18 @@ fold_builtin_pow (location_t loc, tree fndecl, tree arg0, tree arg1, tree type) } } - /* Optimize pow(pow(x,y),z) = pow(x,y*z). */ + /* Optimize pow(pow(x,y),z) = pow(x,y*z) iff x is nonnegative. */ if (fcode == BUILT_IN_POW || fcode == BUILT_IN_POWF || fcode == BUILT_IN_POWL) { tree arg00 = CALL_EXPR_ARG (arg0, 0); - tree arg01 = CALL_EXPR_ARG (arg0, 1); - tree narg1 = fold_build2_loc (loc, MULT_EXPR, type, arg01, arg1); - return build_call_expr_loc (loc, fndecl, 2, arg00, narg1); + if (tree_expr_nonnegative_p (arg00)) + { + tree arg01 = CALL_EXPR_ARG (arg0, 1); + tree narg1 = fold_build2_loc (loc, MULT_EXPR, type, arg01, arg1); + return build_call_expr_loc (loc, fndecl, 2, arg00, narg1); + } } } |