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[Bug tree-optimization/15349] [tree-ssa] Merge two phi nodes.
- From: "kazu at cs dot umass dot edu" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 14 Sep 2004 03:53:07 -0000
- Subject: [Bug tree-optimization/15349] [tree-ssa] Merge two phi nodes.
- References: <20040509194800.15349.kazu@cs.umass.edu>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Additional Comments From kazu at cs dot umass dot edu 2004-09-14 03:53 -------
Well, this occurs everywhere, but just give you an example, sometimes
a chain of PHI goes as long as
<L126>:;
# iftmp.32_81 = PHI <0(69), 5(70)>;
<L128>:;
# iftmp.32_83 = PHI <7(67), 6(68), iftmp.32_81(71)>;
<L132>:;
# iftmp.32_78 = PHI <iftmp.32_83(72), 16(62), iftmp.32_79(66), 0(61)>;
<L134>:;
# iftmp.32_84 = PHI <2(55), iftmp.32_75(59), iftmp.32_78(73)>;
<L137>:;
# iftmp.32_86 = PHI <4(53), 3(54), iftmp.32_84(74)>;
<L141>:;
# iftmp.32_74 = PHI <iftmp.32_86(75), 14(51), 0(50), 14(49), 1(52)>;
<L144>:;
# iftmp.32_70 = PHI <iftmp.32_74(76), 15(42), 0(41), 15(40), iftmp.32_71(47)>;
<L146>:;
# iftmp.32_89 = PHI <8(37), 8(38), iftmp.32_70(77)>;
<L150>:;
# iftmp.32_91 = PHI <12(35), 11(36), iftmp.32_89(78)>;
<L154>:;
This comes from reload_cse_simplify_operands() in postreload.c.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15349