Hi!
On 32-bit HWI warning there is a warning about signed (INTVAL) vs. unsigned
({,op_}precision) comparison (on 64-bit HWI that doesn't trigger, as
INTVAL is 64-bit signed long, while precision is 32-bit unsigned).
This patch fixes the warning and makes sure we don't try to optimize
shifts by negative count.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2012-10-10 Jakub Jelinek <ja...@redhat.com>
PR middle-end/54862
* simplify-rtx.c (simplify_truncation): Compare UINTVAL instead of
INTVAL of second argument with precision resp. op_precision.
--- gcc/simplify-rtx.c.jj 2012-10-08 21:37:33.000000000 +0200
+++ gcc/simplify-rtx.c 2012-10-09 13:48:24.269969321 +0200
@@ -668,7 +668,7 @@ simplify_truncation (enum machine_mode m
&& CONST_INT_P (XEXP (op, 1))
&& GET_CODE (XEXP (op, 0)) == SIGN_EXTEND
&& GET_MODE (XEXP (XEXP (op, 0), 0)) == mode
- && INTVAL (XEXP (op, 1)) < precision)
+ && UINTVAL (XEXP (op, 1)) < precision)
return simplify_gen_binary (ASHIFTRT, mode,
XEXP (XEXP (op, 0), 0), XEXP (op, 1));
@@ -680,7 +680,7 @@ simplify_truncation (enum machine_mode m
&& CONST_INT_P (XEXP (op, 1))
&& GET_CODE (XEXP (op, 0)) == ZERO_EXTEND
&& GET_MODE (XEXP (XEXP (op, 0), 0)) == mode
- && INTVAL (XEXP (op, 1)) < precision)
+ && UINTVAL (XEXP (op, 1)) < precision)
return simplify_gen_binary (LSHIFTRT, mode,
XEXP (XEXP (op, 0), 0), XEXP (op, 1));
@@ -692,7 +692,7 @@ simplify_truncation (enum machine_mode m
&& (GET_CODE (XEXP (op, 0)) == ZERO_EXTEND
|| GET_CODE (XEXP (op, 0)) == SIGN_EXTEND)
&& GET_MODE (XEXP (XEXP (op, 0), 0)) == mode
- && INTVAL (XEXP (op, 1)) < precision)
+ && UINTVAL (XEXP (op, 1)) < precision)
return simplify_gen_binary (ASHIFT, mode,
XEXP (XEXP (op, 0), 0), XEXP (op, 1));
@@ -705,8 +705,7 @@ simplify_truncation (enum machine_mode m
&& 2 * precision <= op_precision
&& CONST_INT_P (XEXP (op, 1))
&& (INTVAL (XEXP (op, 1)) & (precision - 1)) == 0
- && INTVAL (XEXP (op, 1)) >= 0
- && INTVAL (XEXP (op, 1)) < op_precision)
+ && UINTVAL (XEXP (op, 1)) < op_precision)
{
int byte = subreg_lowpart_offset (mode, op_mode);
int shifted_bytes = INTVAL (XEXP (op, 1)) / BITS_PER_UNIT;
Jakub
