| Message ID | 20120202081516.GX18768@tyan-ft48-01.lab.bos.redhat.com |
|---|---|
| State | New |
| Headers | show |
On Thu, Feb 2, 2012 at 9:15 AM, Jakub Jelinek <jakub@redhat.com> wrote: > This peephole, as shown on the testcase, happily transforms a QImode > memory load into a register, followed by SImode addition of that reg and > %ebp, followed by QImode store of that back into the same memory and > QImode comparison of that with zero into a QImode addition of the register > to the memory with setting flags instead of clobbering them. The problem > with that is that for -m32 %ebp can't be used in QImode instructions. > > Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, > ok for trunk? > > 2012-02-02 Jakub Jelinek <jakub@redhat.com> > > PR target/52086 > * config/i386/i386.md (*addqi_2 peephole with SImode addition): Check > that operands[2] is either immediate, or q_regs_operand. > > * gcc.dg/pr52086.c: New test. OK, probably we also need to backport this fix to other release branches. Thanks, Uros.
On Thu, Feb 02, 2012 at 10:02:09AM +0100, Uros Bizjak wrote: > OK, Thanks. > probably we also need to backport this fix to other release branches. No, while I didn't remember it, svn blame revealed that these peepholes were my fault, added for PR49095 just for 4.7+. Jakub
--- gcc/config/i386/i386.md.jj 2012-01-13 21:47:34.000000000 +0100 +++ gcc/config/i386/i386.md 2012-02-01 22:42:57.805296347 +0100 @@ -17232,6 +17232,9 @@ (define_peephole2 && REG_P (operands[0]) && REG_P (operands[4]) && REGNO (operands[0]) == REGNO (operands[4]) && peep2_reg_dead_p (4, operands[0]) + && (<MODE>mode != QImode + || immediate_operand (operands[2], SImode) + || q_regs_operand (operands[2], SImode)) && !reg_overlap_mentioned_p (operands[0], operands[1]) && ix86_match_ccmode (peep2_next_insn (3), (GET_CODE (operands[3]) == PLUS --- gcc/testsuite/gcc.dg/pr52086.c.jj 2012-02-01 22:56:54.520519545 +0100 +++ gcc/testsuite/gcc.dg/pr52086.c 2012-02-01 22:56:35.000000000 +0100 @@ -0,0 +1,21 @@ +/* PR target/52086 */ +/* { dg-do compile } */ +/* { dg-options "-O2" } */ +/* { dg-additional-options "-fpic" { target fpic } } */ + +struct S { char a; char b[100]; }; +int bar (void); +int baz (int); + +void +foo (struct S *x) +{ + if (bar () & 1) + { + char c = bar (); + baz (4); + x->a += c; + while (x->a) + x->b[c] = bar (); + } +}