r246504 - in /branches/ibm/gcc-6-branch/gcc: Ch...

[acsawdey@gcc.gnu.org]

Author: acsawdey
Date: Mon Mar 27 15:40:20 2017
New Revision: 246504

URL: https://gcc.gnu.org/viewcvs?rev=246504&root=gcc&view=rev
Log:
2017-03-27  Aaron Sawdey  <acsawdey@linux.vnet.ibm.com>

	Backport from trunk
	PR target/79449
	PR target/79170

	* gcc.dg/strncmp-2.c: New.  Test strncmp and memcmp builtin expansion
	for reading beyond a 4k boundary.
	* config/rs6000/rs6000.c (expand_block_compare): Make sure runtime
	boundary crossing check and subsequent code generation agree.
	* gcc.dg/memcmp-1.c: Improved to catch failures seen in PR 79170.
	* config/rs6000/altivec.md (*setb_internal): Rename to setb_signed.
	(setb_unsigned) New pattern for setb with CCUNS.
	* config/rs6000/rs6000.c (expand_block_compare): Use a different
	subfc./subfe sequence to avoid overflow problems.  Generate a
	shorter sequence with cmpld/setb for power9.
	* config/rs6000/rs6000.md (subf<mode>3_carry_dot2): Add a new pattern
	for generating subfc. instruction.
	(cmpstrsi): Add TARGET_POPCNTD predicate as the generate sequence
	now uses this instruction.
	* config/rs6000/rs6000-protos.h (expand_strn_compare): Add arg.
	* config/rs6000/rs6000.c (expand_strn_compare): Add ability to expand
	strcmp. Fix bug where comparison didn't stop with zero byte. Fix
	case where N arg is SIZE_MAX.
	* config/rs6000/rs6000.md (cmpstrnsi): Args to expand_strn_compare.
	(cmpstrsi): Add pattern.
	* gcc.dg/memcmp-1.c: New.
	* gcc.dg/strncmp-1.c: New.
	* config/rs6000/rs6000-protos.h (expand_strn_compare): Declare.
	* config/rs6000/rs6000.md (UNSPEC_CMPB): New unspec.
	(cmpb<mode>3): pattern for generating cmpb.
	(cmpstrnsi): pattern to expand strncmp ().
	* config/rs6000/rs6000.opt (mstring-compare-inline-limit): Add a new
	target option for controlling how much code inline expansion of
	strncmp() will be allowed to generate.
	* config/rs6000/rs6000.c (expand_strncmp_align_check): generate code
	for runtime page crossing check of strncmp () args.
	(expand_strn_compare): Function to do builtin expansion of strncmp ().
	* config/i386/i386.md (cmpstrnsi): New test to bail out if neither
	string input is a string constant.
	* builtins.c (expand_builtin_strncmp): Attempt expansion of strncmp
	via cmpstrnsi even if neither string is constant.



Modified:
    branches/ibm/gcc-6-branch/gcc/ChangeLog.ibm
    branches/ibm/gcc-6-branch/gcc/builtins.c
    branches/ibm/gcc-6-branch/gcc/config/i386/i386.md
    branches/ibm/gcc-6-branch/gcc/config/rs6000/altivec.md
    branches/ibm/gcc-6-branch/gcc/config/rs6000/rs6000-protos.h
    branches/ibm/gcc-6-branch/gcc/config/rs6000/rs6000.c
    branches/ibm/gcc-6-branch/gcc/config/rs6000/rs6000.md
    branches/ibm/gcc-6-branch/gcc/config/rs6000/rs6000.opt