| Message ID | 20130609085724.GM1493@tucnak.redhat.com |
|---|---|
| State | New |
| Headers | show |
On Sun, Jun 9, 2013 at 10:57 AM, Jakub Jelinek <jakub@redhat.com> wrote: > These two peephole2s misbehave if it sees e.g. > regN = mem > regN = regN + regN > mem = regN > CC = regN != 0 > because transforming it into > mem = mem + regN ; CC = mem != 0 > is wrong, I forgot to verify the second operand of the > plusminuslogic_operator doesn't overlap the first operand. > > Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok for > trunk/4.8 and perhaps also 4.7 (where it is just latent)? > > 2013-06-09 Jakub Jelinek <jakub@redhat.com> > > PR target/57568 > * config/i386/i386.md (TARGET_READ_MODIFY_WRITE peepholes): Ensure > that operands[2] doesn't overlap with operands[0]. > > * gcc.c-torture/execute/pr57568.c: New test. The patch is OK everywhere. Thanks, Uros.
--- gcc/config/i386/i386.md.jj 2013-06-03 19:15:34.000000000 +0200 +++ gcc/config/i386/i386.md 2013-06-08 21:59:43.416954936 +0200 @@ -16591,6 +16591,7 @@ (define_peephole2 "(TARGET_READ_MODIFY_WRITE || optimize_insn_for_size_p ()) && peep2_reg_dead_p (4, operands[0]) && !reg_overlap_mentioned_p (operands[0], operands[1]) + && !reg_overlap_mentioned_p (operands[0], operands[2]) && (<MODE>mode != QImode || immediate_operand (operands[2], QImode) || q_regs_operand (operands[2], QImode)) @@ -16655,6 +16656,7 @@ (define_peephole2 || immediate_operand (operands[2], SImode) || q_regs_operand (operands[2], SImode)) && !reg_overlap_mentioned_p (operands[0], operands[1]) + && !reg_overlap_mentioned_p (operands[0], operands[2]) && ix86_match_ccmode (peep2_next_insn (3), (GET_CODE (operands[3]) == PLUS || GET_CODE (operands[3]) == MINUS) --- gcc/testsuite/gcc.c-torture/execute/pr57568.c.jj 2013-06-08 22:03:38.861005658 +0200 +++ gcc/testsuite/gcc.c-torture/execute/pr57568.c 2013-06-08 22:03:19.000000000 +0200 @@ -0,0 +1,12 @@ +/* PR target/57568 */ + +extern void abort (void); +int a[6][9] = { }, b = 1, *c = &a[3][5]; + +int +main () +{ + if (b && (*c = *c + *c)) + abort (); + return 0; +}