This repairs the bootstrap issue due to unsafe signed overflow
assumptions. Bootstrapped and tested on powerpc64-unknown-linux-gnu
with no new regressions. Ok for trunk?
Thanks,
Bill
2012-05-18 Bill Schmidt <wschm...@linux.vnet.ibm.com>
* config/rs6000/rs6000.c (print_operand): Revise code that unsafely
relied on signed overflow behavior.
Index: gcc/config/rs6000/rs6000.c
===================================================================
--- gcc/config/rs6000/rs6000.c (revision 187651)
+++ gcc/config/rs6000/rs6000.c (working copy)
@@ -14679,7 +14679,6 @@ void
print_operand (FILE *file, rtx x, int code)
{
int i;
- HOST_WIDE_INT val;
unsigned HOST_WIDE_INT uval;
switch (code)
@@ -15120,34 +15119,17 @@ print_operand (FILE *file, rtx x, int code)
case 'W':
/* MB value for a PowerPC64 rldic operand. */
- val = (GET_CODE (x) == CONST_INT
- ? INTVAL (x) : CONST_DOUBLE_HIGH (x));
+ i = clz_hwi (GET_CODE (x) == CONST_INT
+ ? INTVAL (x) : CONST_DOUBLE_HIGH (x));
- if (val < 0)
- i = -1;
- else
- for (i = 0; i < HOST_BITS_PER_WIDE_INT; i++)
- if ((val <<= 1) < 0)
- break;
-
#if HOST_BITS_PER_WIDE_INT == 32
- if (GET_CODE (x) == CONST_INT && i >= 0)
+ if (GET_CODE (x) == CONST_INT && i > 0)
i += 32; /* zero-extend high-part was all 0's */
else if (GET_CODE (x) == CONST_DOUBLE && i == 32)
- {
- val = CONST_DOUBLE_LOW (x);
-
- gcc_assert (val);
- if (val < 0)
- --i;
- else
- for ( ; i < 64; i++)
- if ((val <<= 1) < 0)
- break;
- }
+ i = clz_hwi (CONST_DOUBLE_LOW (x)) + 32;
#endif
- fprintf (file, "%d", i + 1);
+ fprintf (file, "%d", i);
return;
case 'x':
