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| author | Richard Henderson <rth@cygnus.com> | 2000-08-11 00:38:23 -0700 |
|---|---|---|
| committer | Richard Henderson <rth@gcc.gnu.org> | 2000-08-11 00:38:23 -0700 |
| commit | f94d0f60d36612acccb50ac4bae4aac9c396c1bc (patch) | |
| tree | 1fb34c9abf221449b5620ee029b478dfd9dbae9b /gcc/combine.c | |
| parent | 9c683c2adc2f3607bf63998f060d1ed2b7791cfd (diff) | |
| download | gcc-f94d0f60d36612acccb50ac4bae4aac9c396c1bc.zip gcc-f94d0f60d36612acccb50ac4bae4aac9c396c1bc.tar.gz gcc-f94d0f60d36612acccb50ac4bae4aac9c396c1bc.tar.bz2 | |
* combine.c (simplify_shift_const): Obey SHIFT_COUNT_TRUNCATED.
From-SVN: r35622
Diffstat (limited to 'gcc/combine.c')
| -rw-r--r-- | gcc/combine.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/gcc/combine.c b/gcc/combine.c index e424317..4ad2f4f 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -8879,10 +8879,11 @@ simplify_shift_const (x, code, result_mode, varop, input_count) ? result_mode : mode); /* Handle cases where the count is greater than the size of the mode - minus 1. For ASHIFT, use the size minus one as the count (this can - occur when simplifying (lshiftrt (ashiftrt ..))). For rotates, - take the count modulo the size. For other shifts, the result is - zero. + minus 1. If SHIFT_COUNT_TRUNCATED, there aren't really any such + cases. Otherwise, for ASHIFT, use the size minus one as the count + (this can occur when simplifying (lshiftrt (ashiftrt ..))). For + rotates, take the count modulo the size. For other shifts, the + result is zero. Since these shifts are being produced by the compiler by combining multiple operations, each of which are defined, we know what the @@ -8890,6 +8891,11 @@ simplify_shift_const (x, code, result_mode, varop, input_count) if (count > GET_MODE_BITSIZE (shift_mode) - 1) { +#ifdef SHIFT_COUNT_TRUNCATED + if (SHIFT_COUNT_TRUNCATED) + count %= GET_MODE_BITSIZE (shift_mode); + else +#endif if (code == ASHIFTRT) count = GET_MODE_BITSIZE (shift_mode) - 1; else if (code == ROTATE || code == ROTATERT) |