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| author | Ulrich Weigand <ulrich.weigand@de.ibm.com> | 2012-10-18 13:16:11 +0000 |
|---|---|---|
| committer | Ulrich Weigand <ulrich.weigand@de.ibm.com> | 2012-10-18 13:16:11 +0000 |
| commit | 6c28a7eec8d1794fb5476cd9fe14affb479ed1d9 (patch) | |
| tree | 1f47a43a375ae85f1595dc7ae797c7bd4a094ba2 /lib/Transforms/Vectorize/LoopVectorize.cpp | |
| parent | 2360b7ad99eedecaae512373e7be49c2143550cf (diff) | |
This patch fixes failures in the SingleSource/Regression/C/uint64_to_float
test case on PowerPC caused by rounding errors when converting from a 64-bit
integer to a single-precision floating point. The reason for this are
double-rounding effects, since on PowerPC we have to convert to an
intermediate double-precision value first, which gets rounded to the
final single-precision result.
The patch fixes the problem by preparing the 64-bit integer so that the
first conversion step to double-precision will always be exact, and the
final rounding step will result in the correctly-rounded single-precision
result. The generated code sequence is equivalent to what GCC would generate.
When -enable-unsafe-fp-math is in effect, that extra effort is omitted
and we accept possible rounding errors (just like GCC does as well).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166178 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms/Vectorize/LoopVectorize.cpp')
0 files changed, 0 insertions, 0 deletions