------- Comment #9 from rearnsha at gcc dot gnu dot org 2010-04-01 15:02
-------
This is a miscompilation during stage2. The file libcpp/expr.c is miscompiled.
The problem is occurring in num_positive, which ends up generating a shift of a
long long right by 63. The code generated is creating spills that are of
SImode variables for the shift output, but then the result is being loaded back
as a DImode object.
Due to scheduling, one of the stores is being moved incorrectly after the load
and we get the following assembly fragment:
342c: fa2b fb02 lsr.w fp, fp, r2
3430: fa0c f003 lsl.w r0, ip, r3
3434: fa2c f301 lsr.w r3, ip, r1
3438: fa2c f202 lsr.w r2, ip, r2
343c: ea40 000b orr.w r0, r0, fp
3440: 9245 str r2, [sp, #276] ; 0x114 <- first part
of store
3442: 4686 mov lr, r0
3444: 2201 movs r2, #1
3446: ea1e 0e21 ands.w lr, lr, r1, asr #32
344a: bf38 it cc
344c: 469e movcc lr, r3
344e: a944 add r1, sp, #272 ; 0x110
3450: e9d1 0100 ldrd r0, r1, [r1] <- Load back
3454: 2300 movs r3, #0
3456: f8cd e110 str.w lr, [sp, #272] ; 0x110 <- Second part
(oops, too late).
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42509
