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| author | liuhongt <hongtao.liu@intel.com> | 2023-06-01 12:11:24 +0800 |
|---|---|---|
| committer | liuhongt <hongtao.liu@intel.com> | 2023-06-03 08:09:31 +0800 |
| commit | 57b30f0134d9b49f7707b0c2ded6fd7686a312c8 (patch) | |
| tree | 0dd7f495d4a14e6555bd8191dabd97dd27b54b1c /libgcc | |
| parent | 49337040865269e13cdc2ead276d12ecb2e9f606 (diff) | |
| download | gcc-57b30f0134d9b49f7707b0c2ded6fd7686a312c8.zip gcc-57b30f0134d9b49f7707b0c2ded6fd7686a312c8.tar.gz gcc-57b30f0134d9b49f7707b0c2ded6fd7686a312c8.tar.bz2 | |
Don't try bswap + rotate when TYPE_PRECISION(n->type) > n->range.
For the testcase in the PR, we have
br64 = br;
br64 = ((br64 << 16) & 0x000000ff00000000ull) | (br64 & 0x0000ff00ull);
n->n: 0x3000000200.
n->range: 32.
n->type: uint64.
The original code assumes n->range is same as TYPE PRECISION(n->type),
and tries to rotate the mask from 0x300000200 -> 0x20300 which is
incorrect. The patch fixed this bug by not trying bswap + rotate when
TYPE_PRECISION(n->type) is not equal to n->range.
gcc/ChangeLog:
PR tree-optimization/110067
* gimple-ssa-store-merging.cc (find_bswap_or_nop): Don't try
bswap + rotate when TYPE_PRECISION(n->type) > n->range.
gcc/testsuite/ChangeLog:
* gcc.target/i386/pr110067.c: New test.
Diffstat (limited to 'libgcc')
0 files changed, 0 insertions, 0 deletions