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| author | Jim Wilson <wilson@gcc.gnu.org> | 1993-04-06 12:38:34 -0700 |
|---|---|---|
| committer | Jim Wilson <wilson@gcc.gnu.org> | 1993-04-06 12:38:34 -0700 |
| commit | 1f1e8172a80d323ea1b6f2843185a5fb2226e2ac (patch) | |
| tree | b0fbf2dc41b326863269226e959e0c282703f2ad /gcc/unroll.c | |
| parent | fdd79c58a2938ccd78e94332a102e74865d2a964 (diff) | |
| download | gcc-1f1e8172a80d323ea1b6f2843185a5fb2226e2ac.zip gcc-1f1e8172a80d323ea1b6f2843185a5fb2226e2ac.tar.gz gcc-1f1e8172a80d323ea1b6f2843185a5fb2226e2ac.tar.bz2 | |
(loop_iterations): When computing comparison_value, use
reg_set_p to identify instructions that modify it.
From-SVN: r4036
Diffstat (limited to 'gcc/unroll.c')
| -rw-r--r-- | gcc/unroll.c | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/gcc/unroll.c b/gcc/unroll.c index b58066d..d93e3ba 100644 --- a/gcc/unroll.c +++ b/gcc/unroll.c @@ -3039,14 +3039,19 @@ loop_iterations (loop_start, loop_end) break; else if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' - && (set = single_set (insn)) - && (SET_DEST (set) == comparison_value)) + && reg_set_p (comparison_value, insn)) { - rtx note = find_reg_note (insn, REG_EQUAL, NULL_RTX); - - if (note && GET_CODE (XEXP (note, 0)) != EXPR_LIST) - comparison_value = XEXP (note, 0); + /* We found the last insn before the loop that sets the register. + If it sets the entire register, and has a REG_EQUAL note, + then use the value of the REG_EQUAL note. */ + if ((set = single_set (insn)) + && (SET_DEST (set) == comparison_value)) + { + rtx note = find_reg_note (insn, REG_EQUAL, NULL_RTX); + if (note && GET_CODE (XEXP (note, 0)) != EXPR_LIST) + comparison_value = XEXP (note, 0); + } break; } } |