diff options
| -rw-r--r-- | gcc/config/arm/arm.c | 31 |
1 files changed, 13 insertions, 18 deletions
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c index aaa9daa..1743980 100644 --- a/gcc/config/arm/arm.c +++ b/gcc/config/arm/arm.c @@ -1531,8 +1531,8 @@ use_return_insn (int iscond, rtx sibling) int const_ok_for_arm (HOST_WIDE_INT i) { - int lowbit; - + unsigned HOST_WIDE_INT mask = ~(unsigned HOST_WIDE_INT)0xFF; + /* For machines with >32 bit HOST_WIDE_INT, the bits above bit 31 must be all zero, or all one. */ if ((i & ~(unsigned HOST_WIDE_INT) 0xffffffff) != 0 @@ -1541,24 +1541,19 @@ const_ok_for_arm (HOST_WIDE_INT i) & ~(unsigned HOST_WIDE_INT) 0xffffffff))) return FALSE; - i &= (unsigned HOST_WIDE_INT) 0xffffffff; - - /* Fast return for 0 and small values. We must do this for zero, since - the code below can't handle that one case. */ - if ((i & ~(unsigned HOST_WIDE_INT) 0xff) == 0) + /* Fast return for 0 and powers of 2 */ + if ((i & (i - 1)) == 0) return TRUE; - /* Get the number of trailing zeros, rounded down to the nearest even - number. */ - lowbit = (ffs ((int) i) - 1) & ~1; - - if ((i & ~(((unsigned HOST_WIDE_INT) 0xff) << lowbit)) == 0) - return TRUE; - else if (lowbit <= 4 - && ((i & ~0xc000003f) == 0 - || (i & ~0xf000000f) == 0 - || (i & ~0xfc000003) == 0)) - return TRUE; + do + { + if ((i & mask & (unsigned HOST_WIDE_INT) 0xffffffff) == 0) + return TRUE; + mask = + (mask << 2) | ((mask & (unsigned HOST_WIDE_INT) 0xffffffff) + >> (32 - 2)) | ~(unsigned HOST_WIDE_INT) 0xffffffff; + } + while (mask != ~(unsigned HOST_WIDE_INT) 0xFF); return FALSE; } |