http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47028
Summary: [4.6 Regression] gcc.dg/tree-ssa/tailrecursion-[57].c
FAIL with -foptimize-sibling-calls
-fno-forward-propagate -fno-tree-copy-prop
-fno-tree-dominator-opts
Product: gcc
Version: 4.6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: rtl-optimization
AssignedTo: [email protected]
ReportedBy: [email protected]
Host: x86_64-pc-linux-gnu
Target: x86_64-pc-linux-gnu
Created attachment 22832
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=22832
reduced testcase
Output:
$ gcc -O -foptimize-sibling-calls -fno-forward-propagate -fno-tree-copy-prop
-fno-tree-dominator-opts pr47028.c
$ ./a.out
Aborted
At the assembly level, fib() is reduced to "return 1;":
fib:
mov eax, 0 # add_acc.0,
add eax, 1 # tmp73,
ret
it seems to first appear in the pr47028.c.179r.combine dump
Tested revision:
r168061 - fail
r165699 - fail
r161659 - OK
4.5 r168062 -OK
