[Bug tree-optimization/77290] New: [7 regression] test case gcc.dg/tree-ssa/pr71347.c fails starting with r239565

[seurer at linux dot vnet.ibm.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77290

            Bug ID: 77290
           Summary: [7 regression] test case gcc.dg/tree-ssa/pr71347.c
                    fails starting with r239565
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: seurer at linux dot vnet.ibm.com
  Target Milestone: ---

PASS: gcc.dg/tree-ssa/pr71347.c (test for excess errors)
FAIL: gcc.dg/tree-ssa/pr71347.c scan-tree-dump-not optimized ".* = MEM.*;"

                === gcc Summary ===

# of expected passes            1
# of unexpected failures        1

This test previously passed on powerpc but began failing with r239565.  From
looking at the test results it looks like it has been failing on other
architectures for quite some time (mid June at least).

Diff of generated .s files:

23c23
<       addi 9,10,8
---
> 	addi 9,10,16
30,31c30,32
<       fmul 12,0,0
<       stfd 12,.LANCHOR0+8@toc@l(8)
---
> 	fmul 0,0,0
> 	fmr 12,0
> 	stfd 0,.LANCHOR0+8@toc@l(8)
37,38d37
<       lfd 0,0(9)
<       addi 9,9,8
40c39,40
<       stfd 0,0(9)
---
> 	addi 9,9,8
> 	stfd 0,-8(9)
61c61
<       .ident  "GCC: (GNU) 7.0.0 20160818 (experimental) [trunk revision
239565]"
---
> 	.ident	"GCC: (GNU) 7.0.0 20160818 (experimental) [trunk revision 239564]"
seurer@genoa:~/gcc/build/gcc-test3$ diff ../gcc-test2/pr71347.s pr71347.s
23c23
<       addi 9,10,16
---
> 	addi 9,10,8
30,32c30,31
<       fmul 0,0,0
<       fmr 12,0
<       stfd 0,.LANCHOR0+8@toc@l(8)
---
> 	fmul 12,0,0
> 	stfd 12,.LANCHOR0+8@toc@l(8)
38c37
<       fmul 0,0,12
---
> 	lfd 0,0(9)
40c39,40
<       stfd 0,-8(9)
---
> 	fmul 0,0,12
> 	stfd 0,0(9)
61c61
<       .ident  "GCC: (GNU) 7.0.0 20160818 (experimental) [trunk revision
239564]"
---
> 	.ident	"GCC: (GNU) 7.0.0 20160818 (experimental) [trunk revision 239565]"