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| author | law <law@138bc75d-0d04-0410-961f-82ee72b054a4> | 1998-10-10 16:03:44 +0000 |
|---|---|---|
| committer | law <law@138bc75d-0d04-0410-961f-82ee72b054a4> | 1998-10-10 16:03:44 +0000 |
| commit | 5d92a54845c0cd1ca923744a5334b7459520f4ec (patch) | |
| tree | a0186dcc34dc8e70af183411fc3bdd7a33f9780b /gcc/regmove.c | |
| parent | 28bae3bfae2510c9f355d12bb59538b811582ee7 (diff) | |
| download | gcc-5d92a54845c0cd1ca923744a5334b7459520f4ec.tar.gz | |
* regmove.c (optimize_reg_copy_3): Honor TRULY_NOOP_TRUNCATION.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@22977 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/regmove.c')
| -rw-r--r-- | gcc/regmove.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/gcc/regmove.c b/gcc/regmove.c index 41235f13704..35ddf12d6f3 100644 --- a/gcc/regmove.c +++ b/gcc/regmove.c @@ -552,6 +552,14 @@ optimize_reg_copy_3 (insn, dest, src) || GET_CODE (SET_SRC (set)) != MEM || SET_DEST (set) != src_reg) return; + + /* Do not use a SUBREG to truncate from one mode to another if truncation + is not a nop. */ + if (GET_MODE_BITSIZE (GET_MODE (src_reg)) <= GET_MODE_BITSIZE (GET_MODE (src)) + && !TRULY_NOOP_TRUNCATION (GET_MODE_BITSIZE (GET_MODE (src)), + GET_MODE_BITSIZE (GET_MODE (src_reg)))) + return; + old_mode = GET_MODE (src_reg); PUT_MODE (src_reg, GET_MODE (src)); XEXP (src, 0) = SET_SRC (set); |