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| author | Roger Sayle <roger@nextmovesoftware.com> | 2022-07-18 07:44:38 +0100 |
|---|---|---|
| committer | Roger Sayle <roger@nextmovesoftware.com> | 2022-07-18 07:44:38 +0100 |
| commit | 2907bfc3412dd8aef6c6acc17f2152a4e0ac4979 (patch) | |
| tree | 3fa532064cc1c2d1d393d0ad90905d3bd604f2fb /gcc/tree-cfg.cc | |
| parent | 43c2505b31adfdef2214318484aaae987fd9e1e0 (diff) | |
| download | gcc-2907bfc3412dd8aef6c6acc17f2152a4e0ac4979.zip gcc-2907bfc3412dd8aef6c6acc17f2152a4e0ac4979.tar.gz gcc-2907bfc3412dd8aef6c6acc17f2152a4e0ac4979.tar.bz2 | |
PR target/106231: Optimize (any_extend:DI (ctz:SI ...)) on x86_64.
This patch resolves PR target/106231 by providing insns that recognize
(zero_extend:DI (ctz:SI ...)) and (sign_extend:DI (ctz:SI ...)). The
result of ctz:SI is always between 0 and 32 (or undefined), so
sign_extension is the same as zero_extension, and the result is already
extended in the destination register.
Things are a little complicated, because the existing implementation
of *ctzsi2 handles multiple cases, including false dependencies, which
we continue to support in this patch.
2022-07-18 Roger Sayle <roger@nextmovesoftware.com>
gcc/ChangeLog
PR target/106231
* config/i386/i386.md (*ctzsidi2_<s>ext): New insn_and_split
to recognize any_extend:DI of ctz:SI which is implicitly extended.
(*ctzsidi2_<s>ext_falsedep): New define_insn to model a DImode
extended ctz:SI that has preceding xor to break false dependency.
gcc/testsuite/ChangeLog
PR target/106231
* gcc.target/i386/pr106231-1.c: New test case.
* gcc.target/i386/pr106231-2.c: New test case.
Diffstat (limited to 'gcc/tree-cfg.cc')
0 files changed, 0 insertions, 0 deletions