The recent patch
* c-parser.c (c_lex_one_token): Do not store the canonical spelling
for keywords.
causes a significant performance regression on SPEC CPU2000 197.parser. With
the above patch, the libc function __ctype_b_loc is called significantly more
times, spending twice the number of cycles in that function. Profiling shows
94K hits for fast version and 190K hits for slow version.
We suspect that this may involve the toupper() calls in strncasecmp.c.
Apparently the canonical name is necessary for some GCC optimization, possibly
the automatic substitution of builtins.
--
Summary: [4.4 Regression] Canonical spelling optimization
dependency
Product: gcc
Version: 4.4.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: normal
Priority: P3
Component: regression
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: dje at gcc dot gnu dot org
GCC build triplet: powerpc*-*-*
GCC host triplet: powerpc*-*-*
GCC target triplet: powerpc*-*-*
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37171
