diff options
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/config/arc/arc.c | 24 |
2 files changed, 29 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 43ae4ea..57e276a 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2013-11-07 Joern Rennecke <joern.rennecke@embecosm.com> + + * config/arc/arc.c (arc_ifcvt): Use commutativity, e.g.: + reg_a := reg_b + reg_a ==> reg_a := reg_a + reg_b + 2013-11-07 Jeff Law <law@redhat.com> * doc/invoke.texi (-fisolate-erroneous-paths): Document. diff --git a/gcc/config/arc/arc.c b/gcc/config/arc/arc.c index 6ddd486..1e0c25e 100644 --- a/gcc/config/arc/arc.c +++ b/gcc/config/arc/arc.c @@ -8203,6 +8203,30 @@ arc_ifcvt (void) { /* ??? don't conditionalize if all side effects are dead in the not-execute case. */ + + /* For commutative operators, we generally prefer to have + the first source match the destination. */ + if (GET_CODE (pat) == SET) + { + rtx src = SET_SRC (pat); + + if (COMMUTATIVE_P (src)) + { + rtx src0 = XEXP (src, 0); + rtx src1 = XEXP (src, 1); + rtx dst = SET_DEST (pat); + + if (rtx_equal_p (src1, dst) && !rtx_equal_p (src0, dst) + /* Leave add_n alone - the canonical form is to + have the complex summand first. */ + && REG_P (src0)) + pat = gen_rtx_SET (VOIDmode, dst, + gen_rtx_fmt_ee (GET_CODE (src), + GET_MODE (src), + src1, src0)); + } + } + /* dwarf2out.c:dwarf2out_frame_debug_expr doesn't know what to do with COND_EXEC. */ if (RTX_FRAME_RELATED_P (insn)) |