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| author | Tamar Christina <tamar.christina@arm.com> | 2023-11-09 14:04:57 +0000 |
|---|---|---|
| committer | Tamar Christina <tamar.christina@arm.com> | 2023-11-09 14:18:52 +0000 |
| commit | ed2e058c58ab064fe3a26bc4a47a5d0a47350f97 (patch) | |
| tree | 0c807a80402401b3c3b222002239b66e356857b8 /libcpp | |
| parent | ffd40d3b233d63c925cceb0dcd5a4fc8925e2993 (diff) | |
| download | gcc-ed2e058c58ab064fe3a26bc4a47a5d0a47350f97.zip gcc-ed2e058c58ab064fe3a26bc4a47a5d0a47350f97.tar.gz gcc-ed2e058c58ab064fe3a26bc4a47a5d0a47350f97.tar.bz2 | |
AArch64: Handle copysign (x, -1) expansion efficiently
copysign (x, -1) is effectively fneg (abs (x)) which on AArch64 can be
most efficiently done by doing an OR of the signbit.
The middle-end will optimize fneg (abs (x)) now to copysign as the
canonical form and so this optimizes the expansion.
If the target has an inclusive-OR that takes an immediate, then the transformed
instruction is both shorter and faster. For those that don't, the immediate
has to be separately constructed, but this still ends up being faster as the
immediate construction is not on the critical path.
Note that this is part of another patch series, the additional testcases
are mutually dependent on the match.pd patch. As such the tests are added
there insteadof here.
gcc/ChangeLog:
PR tree-optimization/109154
* config/aarch64/aarch64.md (copysign<GPF:mode>3): Handle
copysign (x, -1).
* config/aarch64/aarch64-simd.md (copysign<mode>3): Likewise.
* config/aarch64/aarch64-sve.md (copysign<mode>3): Likewise.
Diffstat (limited to 'libcpp')
0 files changed, 0 insertions, 0 deletions