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| author | Roger Sayle <roger@eyesopen.com> | 2003-08-26 13:22:14 +0000 |
|---|---|---|
| committer | Roger Sayle <sayle@gcc.gnu.org> | 2003-08-26 13:22:14 +0000 |
| commit | cf42869d28e645cd7bffb3a3a948807dffb93d6b (patch) | |
| tree | c8a37390f8dba8c2397917760e73ce8179a365a1 /gcc/simplify-rtx.c | |
| parent | a103ca2cde431b09326d1378eaaefd45de7bc3af (diff) | |
| download | gcc-cf42869d28e645cd7bffb3a3a948807dffb93d6b.zip gcc-cf42869d28e645cd7bffb3a3a948807dffb93d6b.tar.gz gcc-cf42869d28e645cd7bffb3a3a948807dffb93d6b.tar.bz2 | |
builtins.c (fold_builtin_bitop): New function to perform constant folding of ffs...
* builtins.c (fold_builtin_bitop): New function to perform constant
folding of ffs, clz, ctz, popcount and parity builtin functions
and their long and long long variants (such as ffsl and ffsll).
(fold_builtin): fold_builtin_bitop when appropriate.
* simplify-rtx.c (simplify_unary_operation): Honor both
CLZ_DEFINED_VALUE_AT_ZERO and CTZ_DEFINED_VALUE_AT_ZERO when
evaluating clz and ctz at compile-time, for operands wider
than HOST_WIDE_INT.
From-SVN: r70806
Diffstat (limited to 'gcc/simplify-rtx.c')
| -rw-r--r-- | gcc/simplify-rtx.c | 21 |
1 files changed, 10 insertions, 11 deletions
diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c index 36a8585..919bea6 100644 --- a/gcc/simplify-rtx.c +++ b/gcc/simplify-rtx.c @@ -649,24 +649,23 @@ simplify_unary_operation (enum rtx_code code, enum machine_mode mode, case CLZ: hv = 0; - if (h1 == 0) - lv = GET_MODE_BITSIZE (mode) - floor_log2 (l1) - 1; - else + if (h1 != 0) lv = GET_MODE_BITSIZE (mode) - floor_log2 (h1) - 1 - HOST_BITS_PER_WIDE_INT; + else if (l1 != 0) + lv = GET_MODE_BITSIZE (mode) - floor_log2 (l1) - 1; + else if (! CLZ_DEFINED_VALUE_AT_ZERO (mode, lv)) + lv = GET_MODE_BITSIZE (mode); break; case CTZ: hv = 0; - if (l1 == 0) - { - if (h1 == 0) - lv = GET_MODE_BITSIZE (mode); - else - lv = HOST_BITS_PER_WIDE_INT + exact_log2 (h1 & -h1); - } - else + if (l1 != 0) lv = exact_log2 (l1 & -l1); + else if (h1 != 0) + lv = HOST_BITS_PER_WIDE_INT + exact_log2 (h1 & -h1); + else if (! CTZ_DEFINED_VALUE_AT_ZERO (mode, lv)) + lv = GET_MODE_BITSIZE (mode); break; case POPCOUNT: |