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| author | Richard Kenner <kenner@gcc.gnu.org> | 1995-12-16 18:16:01 -0500 |
|---|---|---|
| committer | Richard Kenner <kenner@gcc.gnu.org> | 1995-12-16 18:16:01 -0500 |
| commit | 058e0bb91b0f9ea8e8e2e1bfe536909e88a0c725 (patch) | |
| tree | 3092f4ddd4dd6afdf38355aed15cf21321dbfca1 | |
| parent | 0c9cabe7d4eec4b2837f89dc5e789be0908ee642 (diff) | |
| download | gcc-058e0bb91b0f9ea8e8e2e1bfe536909e88a0c725.zip gcc-058e0bb91b0f9ea8e8e2e1bfe536909e88a0c725.tar.gz gcc-058e0bb91b0f9ea8e8e2e1bfe536909e88a0c725.tar.bz2 | |
(optimize_reg_copy_2): Don't attempt optimization if destination
register dies.
From-SVN: r10780
| -rw-r--r-- | gcc/local-alloc.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/gcc/local-alloc.c b/gcc/local-alloc.c index 647b2d5..9d941fe 100644 --- a/gcc/local-alloc.c +++ b/gcc/local-alloc.c @@ -865,7 +865,7 @@ optimize_reg_copy_1 (insn, dest, src) In that case, we can replace all uses of DEST, starting with INSN and ending with the set of SRC to DEST, with SRC. We do not do this optimization if a CALL_INSN is crossed unless SRC already crosses a - call. + call or if DEST dies before the copy back to SRC. It is assumed that DEST and SRC are pseudos; it is too complicated to do this for hard registers since the substitutions we may make might fail. */ @@ -930,6 +930,7 @@ optimize_reg_copy_2 (insn, dest, src) } if (reg_set_p (src, p) + || find_reg_note (p, REG_DEAD, dest) || (GET_CODE (p) == CALL_INSN && reg_n_calls_crossed[sregno] == 0)) break; } |