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| author | Segher Boessenkool <segher@kernel.crashing.org> | 2014-10-02 04:18:01 +0200 |
|---|---|---|
| committer | Segher Boessenkool <segher@gcc.gnu.org> | 2014-10-02 04:18:01 +0200 |
| commit | fef32cf89f7fe0c8864443dca942c6e34a204976 (patch) | |
| tree | 002696394921c8abd7ea2ffccb3f77aae36b575c /gcc/combine.c | |
| parent | 3f4dd27a6e582dd3e072656c61c61f2208c11a86 (diff) | |
| download | gcc-fef32cf89f7fe0c8864443dca942c6e34a204976.zip gcc-fef32cf89f7fe0c8864443dca942c6e34a204976.tar.gz gcc-fef32cf89f7fe0c8864443dca942c6e34a204976.tar.bz2 | |
re PR rtl-optimization/62151 (wrong code at -O2 and -O3 on x86_64-linux-gnu)
2014-10-01 Segher Boessenkool <segher@kernel.crashing.org>
gcc/
PR rtl-optimization/62151
* combine.c (can_combine_p): Allow the destination register of INSN
to be clobbered in I3.
(subst): Do not substitute into clobbers of registers.
gcc/testsuite/
* gcc.dg/combine-clobber.c: New.
From-SVN: r215789
Diffstat (limited to 'gcc/combine.c')
| -rw-r--r-- | gcc/combine.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/gcc/combine.c b/gcc/combine.c index 1457eab..ff5f0db 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -1950,11 +1950,7 @@ can_combine_p (rtx_insn *insn, rtx_insn *i3, rtx_insn *pred ATTRIBUTE_UNUSED, for (i = XVECLEN (PATTERN (i3), 0) - 1; i >= 0; i--) if (GET_CODE (XVECEXP (PATTERN (i3), 0, i)) == CLOBBER) { - /* Don't substitute for a register intended as a clobberable - operand. */ rtx reg = XEXP (XVECEXP (PATTERN (i3), 0, i), 0); - if (rtx_equal_p (reg, dest)) - return 0; /* If the clobber represents an earlyclobber operand, we must not substitute an expression containing the clobbered register. @@ -4963,6 +4959,11 @@ subst (rtx x, rtx from, rtx to, int in_dest, int in_cond, int unique_copy) || (REG_P (X) && REG_P (Y) \ && REGNO (X) == REGNO (Y) && GET_MODE (X) == GET_MODE (Y))) + /* Do not substitute into clobbers of regs -- this will never result in + valid RTL. */ + if (GET_CODE (x) == CLOBBER && REG_P (XEXP (x, 0))) + return x; + if (! in_dest && COMBINE_RTX_EQUAL_P (x, from)) { n_occurrences++; |