From 1bc5aee63eb72b341f506ad058502cd0361f0d10 Mon Sep 17 00:00:00 2001 From: Ben Cheng Date: Tue, 25 Mar 2014 22:37:19 -0700 Subject: Initial checkin of GCC 4.9.0 from trunk (r208799). Change-Id: I48a3c08bb98542aa215912a75f03c0890e497dba --- gcc-4.9/gcc/testsuite/gcc.target/spu/dfcgt-nan.c | 31 ++++++++++++++++++++++++ 1 file changed, 31 insertions(+) create mode 100644 gcc-4.9/gcc/testsuite/gcc.target/spu/dfcgt-nan.c (limited to 'gcc-4.9/gcc/testsuite/gcc.target/spu/dfcgt-nan.c') 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); +} -- cgit v1.2.3