diff options
| author | ktkachov <ktkachov@138bc75d-0d04-0410-961f-82ee72b054a4> | 2016-01-05 16:06:06 +0000 |
|---|---|---|
| committer | ktkachov <ktkachov@138bc75d-0d04-0410-961f-82ee72b054a4> | 2016-01-05 16:06:06 +0000 |
| commit | 1e9147dd7b41b6e32c25501b50df73e74b75387f (patch) | |
| tree | 2b0e98778dcdae9cd360e0673ccdbcb12c249605 /gcc/combine.c | |
| parent | d42aa6198a400c3a3c5212bb15c5748ea3dc230c (diff) | |
[combine][v2] Canonicalise (r + r) to (r << 1) to aid recognition
PR rtl-optimization/68651
* combine.c (combine_simplify_rtx): Canonicalize x + x into
x << 1.
* gcc.target/aarch64/pr68651_1.c: New test.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@232077 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/combine.c')
| -rw-r--r-- | gcc/combine.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/gcc/combine.c b/gcc/combine.c index fd384881cd6..d088031b853 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -5895,6 +5895,13 @@ combine_simplify_rtx (rtx x, machine_mode op0_mode, int in_dest, || XEXP (temp, 1) != XEXP (x, 0))))) return temp; } + + /* Canonicalize x + x into x << 1. */ + if (GET_MODE_CLASS (mode) == MODE_INT + && rtx_equal_p (XEXP (x, 0), XEXP (x, 1)) + && !side_effects_p (XEXP (x, 0))) + return simplify_gen_binary (ASHIFT, mode, XEXP (x, 0), const1_rtx); + break; case MINUS: |