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| author | Richard Henderson <rth@redhat.com> | 2003-02-05 14:37:54 -0800 |
|---|---|---|
| committer | Richard Henderson <rth@gcc.gnu.org> | 2003-02-05 14:37:54 -0800 |
| commit | 7dba8395e27f52d22aa11ff2fc147858e34f2a9d (patch) | |
| tree | e14ea46575bce454a67edbb9d6bc03000c970bcd /gcc/combine.c | |
| parent | 8d705469aaefd27a439760de0c216ff036f92e11 (diff) | |
| download | gcc-7dba8395e27f52d22aa11ff2fc147858e34f2a9d.zip gcc-7dba8395e27f52d22aa11ff2fc147858e34f2a9d.tar.gz gcc-7dba8395e27f52d22aa11ff2fc147858e34f2a9d.tar.bz2 | |
defaults.h (CLZ_DEFINED_VALUE_AT_ZERO): New.
* defaults.h (CLZ_DEFINED_VALUE_AT_ZERO): New.
(CTZ_DEFINED_VALUE_AT_ZERO): New.
* doc/rtl.texi, doc/tm.texi: Document them.
* combine.c (nonzero_bits) [CLZ, CTZ]: Handle the definedness
of the value at zero properly.
* fold-const.c (tree_expr_nonnegative_p): Likewise.
* simplify-rtx.c (simplify_unary_operation): Likewise.
* config/alpha/alpha.h (CLZ_DEFINED_VALUE_AT_ZERO): New.
(CTZ_DEFINED_VALUE_AT_ZERO): New.
* config/arm/arm.c (TARGET_INIT_BUILTINS): Remove.
(TARGET_EXPAND_BUILTIN): Remove.
(def_builtin, arm_init_builtins, arm_expand_builtin): Remove.
* config/arm/arm.h (CLZ_DEFINED_VALUE_AT_ZERO): New.
(enum arm_builtins): Remove.
* config/arm/arm.md (UNSPEC_CLZ): Remove.
(clzsi2): Rename from clz; use clz instead of unspec.
(ctzsi2): New.
* config/arm/arm-protos.h: Update.
From-SVN: r62453
Diffstat (limited to 'gcc/combine.c')
| -rw-r--r-- | gcc/combine.c | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/gcc/combine.c b/gcc/combine.c index aeb5c2f..6566823 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -8547,11 +8547,28 @@ nonzero_bits (x, mode) break; case FFS: - case CLZ: - case CTZ: case POPCOUNT: /* This is at most the number of bits in the mode. */ - nonzero = ((HOST_WIDE_INT) 1 << (floor_log2 (mode_width) + 1)) - 1; + nonzero = ((HOST_WIDE_INT) 2 << (floor_log2 (mode_width))) - 1; + break; + + case CLZ: + /* If CLZ has a known value at zero, then the nonzero bits are + that value, plus the number of bits in the mode minus one. */ + if (CLZ_DEFINED_VALUE_AT_ZERO (mode, nonzero)) + nonzero |= ((HOST_WIDE_INT) 1 << (floor_log2 (mode_width))) - 1; + else + nonzero = -1; + break; + + case CTZ: + /* If CTZ has a known value at zero, then the nonzero bits are + that value, plus the number of bits in the mode minus one. */ + if (CTZ_DEFINED_VALUE_AT_ZERO (mode, nonzero)) + nonzero |= ((HOST_WIDE_INT) 1 << (floor_log2 (mode_width))) - 1; + else + nonzero = -1; + break; break; case PARITY: |