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author | Ben Cheng <bccheng@google.com> | 2014-03-25 22:37:19 -0700 |
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committer | Ben Cheng <bccheng@google.com> | 2014-03-25 22:37:19 -0700 |
commit | 1bc5aee63eb72b341f506ad058502cd0361f0d10 (patch) | |
tree | c607e8252f3405424ff15bc2d00aa38dadbb2518 /gcc-4.9/gcc/testsuite/gcc.target/spu/dfcgt-nan.c | |
parent | 283a0bf58fcf333c58a2a92c3ebbc41fb9eb1fdb (diff) | |
download | toolchain_gcc-1bc5aee63eb72b341f506ad058502cd0361f0d10.tar.gz toolchain_gcc-1bc5aee63eb72b341f506ad058502cd0361f0d10.tar.bz2 toolchain_gcc-1bc5aee63eb72b341f506ad058502cd0361f0d10.zip |
Initial checkin of GCC 4.9.0 from trunk (r208799).
Change-Id: I48a3c08bb98542aa215912a75f03c0890e497dba
Diffstat (limited to 'gcc-4.9/gcc/testsuite/gcc.target/spu/dfcgt-nan.c')
-rw-r--r-- | gcc-4.9/gcc/testsuite/gcc.target/spu/dfcgt-nan.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/gcc-4.9/gcc/testsuite/gcc.target/spu/dfcgt-nan.c b/gcc-4.9/gcc/testsuite/gcc.target/spu/dfcgt-nan.c new file mode 100644 index 000000000..18ce01356 --- /dev/null +++ b/gcc-4.9/gcc/testsuite/gcc.target/spu/dfcgt-nan.c @@ -0,0 +1,31 @@ +/* { dg-do compile } */ +/* { dg-options "-march=celledp -O1" } */ +/* { dg-final { scan-assembler "dfceq" } } */ + +/* GCC previously transformed an "a <= b" test into "! (a > b)" when + compiling with -march=celledp, so that the dfcgt instruction can be + used to implement the comparison. + + However, this transformation violates the IEEE-754 standard in the + presence of NaN values. If either a or b is a NaN, a <= b should + evaluate to false according to IEEE rules. However, after the + transformation, a > b as implemented by dfcgt itself returns false, + so the transformed test returns true. + + Note that the equivalent transformation is valid for single- + precision floating-point values on the Cell SPU, because the format + does not have NaNs. It is invalid for double-precision, even on + Cell, however. */ + +int test (double a, double b) __attribute__ ((noinline)); +int test (double a, double b) +{ + return a <= b; +} + +int main (void) +{ + double x = 0.0; + double y = 0.0/0.0; + return test (x, y); +} |