diff options
Diffstat (limited to 'gcc/simplify-rtx.c')
| -rw-r--r-- | gcc/simplify-rtx.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c index 9f50ed9459f..0f11556251d 100644 --- a/gcc/simplify-rtx.c +++ b/gcc/simplify-rtx.c @@ -2587,7 +2587,18 @@ simplify_subreg (outermode, op, innermode, byte) arguments are passed on 32-bit Sparc and should be fixed. */ if (HARD_REGNO_MODE_OK (final_regno, outermode) || ! HARD_REGNO_MODE_OK (REGNO (op), innermode)) - return gen_rtx_REG (outermode, final_regno); + { + rtx x = gen_rtx_REG (outermode, final_regno); + + /* Propagate original regno. We don't have any way to specify + the offset inside orignal regno, so do so only for lowpart. + The information is used only by alias analysis that can not + grog partial register anyway. */ + + if (subreg_lowpart_offset (outermode, innermode) == byte) + ORIGINAL_REGNO (x) = ORIGINAL_REGNO (op); + return x; + } } /* If we have a SUBREG of a register that we are replacing and we are |