| Message ID | 87inro3ewx.fsf@e105548-lin.cambridge.arm.com |
|---|---|
| State | New |
| Headers | show |
On 11/15/2016 09:07 AM, Richard Sandiford wrote: > After simplifying the operands of a PLUS, canon_rtx checked only > for cases in which one of the simplified operands was a constant, > falling back to gen_rtx_PLUS otherwise. This left the PLUS in a > non-canonical order if one of the simplified operands was > (plus (reg R1) (const_int X)); we'd end up with: > > (plus (plus (reg R1) (const_int Y)) (reg R2)) > > rather than: > > (plus (plus (reg R1) (reg R2)) (const_int Y)) > > Fixing this exposed new DSE opportunities on spu-elf in > gcc.c-torture/execute/builtins/strcat-chk.c but otherwise > it doesn't seem to have much practical effect. > > Tested on aarch64-linux-gnu and x86_64-linux-gnu. OK to install? > > Thanks, > Richard > > > [ This patch is part of the SVE series posted here: > https://gcc.gnu.org/ml/gcc/2016-11/msg00030.html ] > > gcc/ > 2016-11-15 Richard Sandiford <richard.sandiford@arm.com> > Alan Hayward <alan.hayward@arm.com> > David Sherwood <david.sherwood@arm.com> > > * alias.c (canon_rtx): Use simplify_gen_binary. OK. jeff
diff --git a/gcc/alias.c b/gcc/alias.c index 486d06a..74df23c 100644 --- a/gcc/alias.c +++ b/gcc/alias.c @@ -1800,13 +1800,7 @@ canon_rtx (rtx x) rtx x1 = canon_rtx (XEXP (x, 1)); if (x0 != XEXP (x, 0) || x1 != XEXP (x, 1)) - { - if (CONST_INT_P (x0)) - return plus_constant (GET_MODE (x), x1, INTVAL (x0)); - else if (CONST_INT_P (x1)) - return plus_constant (GET_MODE (x), x0, INTVAL (x1)); - return gen_rtx_PLUS (GET_MODE (x), x0, x1); - } + return simplify_gen_binary (PLUS, GET_MODE (x), x0, x1); } /* This gives us much better alias analysis when called from