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| author | Michael Meissner <meissner@linux.vnet.ibm.com> | 2010-12-08 16:34:20 +0000 |
|---|---|---|
| committer | Michael Meissner <meissner@gcc.gnu.org> | 2010-12-08 16:34:20 +0000 |
| commit | b0ce92b4038fa29a390186c9eb03f1f1cfa8dd56 (patch) | |
| tree | d6a2589788d2d96ce23e4a18e6a6325f473bfe53 /gcc | |
| parent | afca0898bc7728495064f251d6094970e036a5c7 (diff) | |
| download | gcc-b0ce92b4038fa29a390186c9eb03f1f1cfa8dd56.zip gcc-b0ce92b4038fa29a390186c9eb03f1f1cfa8dd56.tar.gz gcc-b0ce92b4038fa29a390186c9eb03f1f1cfa8dd56.tar.bz2 | |
PR 42694: add checks to make sure sqrt is supported
From-SVN: r167594
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 8 | ||||
| -rw-r--r-- | gcc/builtins.c | 6 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.target/powerpc/ppc-pow.c | 34 |
4 files changed, 52 insertions, 2 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 92b01db..6428570 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,11 @@ +2010-12-08 Michael Meissner <meissner@linux.vnet.ibm.com> + + PR middle-end/42694 + * builtins.c (expand_builtin_pow_root): Don't optimize pow(x,y) + where y is 0.25, 1./6., or 0.75 if the target does not have a sqrt + instruction, but do optimize if y is 0.5 or 1./3. since that + changes an expensive call into a cheaper one. + 2010-12-08 Richard Guenther <rguenther@suse.de> * tree-ssa-sccvn.c (copy_reference_ops_from_ref): Use a shift diff --git a/gcc/builtins.c b/gcc/builtins.c index 2816a7e..eb2aa3e 100644 --- a/gcc/builtins.c +++ b/gcc/builtins.c @@ -3068,7 +3068,8 @@ expand_builtin_pow_root (location_t loc, tree arg0, tree arg1, tree type, if (REAL_VALUES_EQUAL (c, dconsthalf)) op = build_call_nofold_loc (loc, sqrtfn, 1, arg0); - else + /* Don't do this optimization if we don't have a sqrt insn. */ + else if (optab_handler (sqrt_optab, mode) != CODE_FOR_nothing) { REAL_VALUE_TYPE dconst1_4 = dconst1; REAL_VALUE_TYPE dconst3_4; @@ -3114,7 +3115,8 @@ expand_builtin_pow_root (location_t loc, tree arg0, tree arg1, tree type, op = build_call_nofold_loc (loc, cbrtfn, 1, arg0); /* Now try 1/6. */ - else if (optimize_insn_for_speed_p ()) + else if (optimize_insn_for_speed_p () + && optab_handler (sqrt_optab, mode) != CODE_FOR_nothing) { REAL_VALUE_TYPE dconst1_6 = dconst1_3; SET_REAL_EXP (&dconst1_6, REAL_EXP (&dconst1_6) - 1); diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 8743d36..7a7f3be 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,9 @@ +2010-12-08 Michael Meissner <meissner@linux.vnet.ibm.com> + + PR middle-end/42694 + * gcc.target/powerpc/ppc-pow.c: New file to make sure pow (x, + 0.75) is not optimized if the machine has no sqrt instruction. + 2010-12-07 Andrey Belevantsev <abel@ispras.ru> PR target/43603 diff --git a/gcc/testsuite/gcc.target/powerpc/ppc-pow.c b/gcc/testsuite/gcc.target/powerpc/ppc-pow.c new file mode 100644 index 0000000..1255d5c --- /dev/null +++ b/gcc/testsuite/gcc.target/powerpc/ppc-pow.c @@ -0,0 +1,34 @@ +/* { dg-do compile { target { { powerpc*-*-* } && { ! powerpc*-apple-darwin* } } } } */ +/* { dg-options "-O2 -ffast-math -mcpu=power6" } */ +/* { dg-final { scan-assembler-times "fsqrt" 3 } } */ +/* { dg-final { scan-assembler-times "fmul" 1 } } */ +/* { dg-final { scan-assembler-times "bl pow" 1 } } */ +/* { dg-final { scan-assembler-times "bl sqrt" 1 } } */ + +double +do_pow_0_75_default (double a) +{ + return __builtin_pow (a, 0.75); /* should generate 2 fsqrts */ +} + +double +do_pow_0_5_default (double a) +{ + return __builtin_pow (a, 0.5); /* should generate fsqrt */ +} + +#pragma GCC target "no-powerpc-gpopt,no-powerpc-gfxopt" + +double +do_pow_0_75_nosqrt (double a) +{ + return __builtin_pow (a, 0.75); /* should call pow */ +} + +double +do_pow_0_5_nosqrt (double a) +{ + return __builtin_pow (a, 0.5); /* should call sqrt */ +} + +#pragma GCC reset_options |