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| author | Eric Botcazou <ebotcazou@gcc.gnu.org> | 2011-04-08 22:31:22 +0000 |
|---|---|---|
| committer | Eric Botcazou <ebotcazou@gcc.gnu.org> | 2011-04-08 22:31:22 +0000 |
| commit | 68bc509a5c4ee2c3179c9430ce9c50dc1f9bfad2 (patch) | |
| tree | 4b379aed7743a6b37efaaade194c8751f93ca0f1 /gcc/combine.c | |
| parent | 51a30b323dd59079cf039341d16e95c6136f31cb (diff) | |
| download | gcc-68bc509a5c4ee2c3179c9430ce9c50dc1f9bfad2.zip gcc-68bc509a5c4ee2c3179c9430ce9c50dc1f9bfad2.tar.gz gcc-68bc509a5c4ee2c3179c9430ce9c50dc1f9bfad2.tar.bz2 | |
combine.c (combine_validate_cost): Adjust comments.
* combine.c (combine_validate_cost): Adjust comments. Set registered
cost of I0 to zero at the end, if any.
From-SVN: r172216
Diffstat (limited to 'gcc/combine.c')
| -rw-r--r-- | gcc/combine.c | 28 |
1 files changed, 15 insertions, 13 deletions
diff --git a/gcc/combine.c b/gcc/combine.c index 8771acf..32a3d73 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -789,14 +789,13 @@ do_SUBST_MODE (rtx *into, enum machine_mode newval) #define SUBST_MODE(INTO, NEWVAL) do_SUBST_MODE(&(INTO), (NEWVAL)) -/* Subroutine of try_combine. Determine whether the combine replacement - patterns NEWPAT, NEWI2PAT and NEWOTHERPAT are cheaper according to - insn_rtx_cost that the original instruction sequence I0, I1, I2, I3 and - undobuf.other_insn. Note that I1 and/or NEWI2PAT may be NULL_RTX. - NEWOTHERPAT and undobuf.other_insn may also both be NULL_RTX. This - function returns false, if the costs of all instructions can be - estimated, and the replacements are more expensive than the original - sequence. */ +/* Subroutine of try_combine. Determine whether the replacement patterns + NEWPAT, NEWI2PAT and NEWOTHERPAT are cheaper according to insn_rtx_cost + than the original sequence I0, I1, I2, I3 and undobuf.other_insn. Note + that I0, I1 and/or NEWI2PAT may be NULL_RTX. Similarly, NEWOTHERPAT and + undobuf.other_insn may also both be NULL_RTX. Return false if the cost + of all the instructions can be estimated and the replacements are more + expensive than the original sequence. */ static bool combine_validate_cost (rtx i0, rtx i1, rtx i2, rtx i3, rtx newpat, @@ -861,10 +860,9 @@ combine_validate_cost (rtx i0, rtx i1, rtx i2, rtx i3, rtx newpat, old_cost = 0; } - /* Disallow this recombination if both new_cost and old_cost are - greater than zero, and new_cost is greater than old cost. */ - if (old_cost > 0 - && new_cost > old_cost) + /* Disallow this combination if both new_cost and old_cost are greater than + zero, and new_cost is greater than old cost. */ + if (old_cost > 0 && new_cost > old_cost) { if (dump_file) { @@ -910,7 +908,11 @@ combine_validate_cost (rtx i0, rtx i1, rtx i2, rtx i3, rtx newpat, INSN_COST (i2) = new_i2_cost; INSN_COST (i3) = new_i3_cost; if (i1) - INSN_COST (i1) = 0; + { + INSN_COST (i1) = 0; + if (i0) + INSN_COST (i0) = 0; + } return true; } |