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| author | Richard Earnshaw <rearnsha@arm.com> | 2012-09-14 17:02:04 +0000 |
|---|---|---|
| committer | Richard Earnshaw <rearnsha@gcc.gnu.org> | 2012-09-14 17:02:04 +0000 |
| commit | 57132d23faff3f5e18d4773892070763bf6a89ca (patch) | |
| tree | 669ec75fa8e27dc3bc1599c04d8fd597458e27c8 /gcc/reload.c | |
| parent | a27d595da25b497f14d8f3714b63819f712cde11 (diff) | |
| download | gcc-57132d23faff3f5e18d4773892070763bf6a89ca.zip gcc-57132d23faff3f5e18d4773892070763bf6a89ca.tar.gz gcc-57132d23faff3f5e18d4773892070763bf6a89ca.tar.bz2 | |
reload.c (find_dummy_reload): Don't use OUT as a reload reg for IN if it overlaps a fixed register.
* reload.c (find_dummy_reload): Don't use OUT as a reload reg
for IN if it overlaps a fixed register.
From-SVN: r191305
Diffstat (limited to 'gcc/reload.c')
| -rw-r--r-- | gcc/reload.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/gcc/reload.c b/gcc/reload.c index f4f3ed0..2e41ed6 100644 --- a/gcc/reload.c +++ b/gcc/reload.c @@ -2036,7 +2036,12 @@ find_dummy_reload (rtx real_in, rtx real_out, rtx *inloc, rtx *outloc, However, we only ignore IN in its role as this reload. If the insn uses IN elsewhere and it contains OUT, that counts. We can't be sure it's the "same" operand - so it might not go through this reload. */ + so it might not go through this reload. + + We also need to avoid using OUT if it, or part of it, is a + fixed register. Modifying such registers, even transiently, + may have undefined effects on the machine, such as modifying + the stack pointer. */ saved_rtx = *inloc; *inloc = const0_rtx; @@ -2049,7 +2054,8 @@ find_dummy_reload (rtx real_in, rtx real_out, rtx *inloc, rtx *outloc, for (i = 0; i < nwords; i++) if (! TEST_HARD_REG_BIT (reg_class_contents[(int) rclass], - regno + i)) + regno + i) + || fixed_regs[regno + i]) break; if (i == nwords) |