https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80416
Bug ID: 80416
Summary: FAIL: g++.dg/torture/pr79671.C -O2 execution test
Product: gcc
Version: 7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: [email protected]
Target Milestone: ---
Target: ia64-*-*
On ia64, pr79671.C fails with -O2, -O3 and -Os, but succeeds with -O1 and -O2
-flto.
When it fails foo looks like this:
0x4000000000000800 <+0>: [MMI] nop.m 0x0
0x4000000000000801 <+1>: st4 [r12]=r0
0x4000000000000802 <+2>: nop.i 0x0;;
0x4000000000000810 <+16>: [MIB] ld4 r8=[r14]
0x4000000000000811 <+17>: nop.i 0x0
0x4000000000000812 <+18>: br.ret.sptk.many b0;;
When it succeeds it looks like this:
0x4000000000000720 <+0>: [MMI] adds r14=4,r12;;
0x4000000000000721 <+1>: st4 [r14]=r0
0x4000000000000722 <+2>: nop.i 0x0;;
0x4000000000000730 <+16>: [MIB] ld4 r8=[r14]
0x4000000000000731 <+17>: nop.i 0x0
0x4000000000000732 <+18>: br.ret.sptk.many b0;;
Looks like the miscompilation happens during the dse1 pass.
