https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80884
Bug ID: 80884 Summary: [8 regression] test case gcc.target/powerpc/20050830-1.c fails starting with r247886 Product: gcc Version: 8.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: seurer at gcc dot gnu.org Target Milestone: --- This test fails on power6 (BE obviously) but still works on power7 and later. The test case is looking for a specific assembler instruction spawn -ignore SIGHUP /home/seurer/gcc/build/gcc-trunk-p6/gcc/xgcc -B/home/seurer/gcc/build/gcc-trunk-p6/gcc/ /home/seurer/gcc/gcc-trunk-p6/gcc/testsuite/gcc.target/powerpc/20050830-1.c -fno-diagnostics-show-caret -fdiagnostics-color=never -O2 -ffat-lto-objects -S -o 20050830-1.s PASS: gcc.target/powerpc/20050830-1.c (test for excess errors) FAIL: gcc.target/powerpc/20050830-1.c scan-assembler bdn and the assembler output changed like this from r247885 to r247886: seurer@makalu-lp1:~/gcc/build/gcc-test$ diff 20050830-1.s.old 20050830-1.s.new 19,30c19,29 < addis 10,2,.LC0@toc@ha < addi 9,3,-512 < rldicl 9,9,56,40 < addi 9,9,1 < ld 8,.LC0@toc@l(10) < addi 10,3,-256 < sldi 3,3,2 < cmpwi 7,10,256 < mtctr 9 < add 3,3,8 < li 9,42 < blt 7,.L7 --- > addis 9,2,.LC0@toc@ha > addi 10,3,-512 > rlwinm 10,10,0,0,23 > subf 10,10,3 > ld 8,.LC0@toc@l(9) > sldi 10,10,2 > sldi 9,3,2 > addi 7,8,-1024 > add 9,9,8 > add 10,10,7 > li 8,42 33,35c32,35 < stw 9,0(3) < addi 3,3,-1024 < bdnz .L3 --- > stw 8,0(9) > addi 9,9,-1024 > cmpld 7,9,10 > bne 7,.L3 38,41d37 < .L7: < li 10,1 < mtctr 10 < b .L3 45c41 < .ident "GCC: (GNU) 8.0.0 20170511 (experimental) [trunk revision 247885]" --- > .ident "GCC: (GNU) 8.0.0 20170511 (experimental) [trunk revision > 247886]" When I tried it with a compiler built for power7 there was no difference is the assembly before/after this revision.