http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55359
Bug #: 55359
Summary: [4.8 Regression] ICE in simplify_subreg accessing an
unaligned subvector
Classification: Unclassified
Product: gcc
Version: 4.8.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: gli...@gcc.gnu.org
I am not quite sure if this code is legal. I noticed it first with a
BIT_FIELD_REF (generated by a local patch), but it also happens with a MEM_REF.
The code generated by 4.7 seems correct, even if it isn't optimal.
$ cat s.c
#include <x86intrin.h>
__m128d f(__m256d x){
return *((__m128d*)((double*)&x+1));
}
$ gcc s.c -mavx2 -S -O2
s.c: In function 'f':
s.c:4:3: internal compiler error: in simplify_subreg, at simplify-rtx.c:5688
return *((__m128d*)((double*)&x+1));
^
0x9052f6 simplify_subreg(machine_mode, rtx_def*, machine_mode, unsigned int)
/data/repos/gcc/pristine/gcc/simplify-rtx.c:5688
0x90b8bd simplify_gen_subreg(machine_mode, rtx_def*, machine_mode, unsigned
int)
/data/repos/gcc/pristine/gcc/simplify-rtx.c:5903
0x6ec7e8 extract_bit_field_1
/data/repos/gcc/pristine/gcc/expmed.c:1482
0x6ecda3 extract_bit_field(rtx_def*, unsigned long, unsigned long, int, bool,
rtx_def*, machine_mode, machine_mode)
/data/repos/gcc/pristine/gcc/expmed.c:1711
0x6fa77e expand_expr_real_1(tree_node*, rtx_def*, machine_mode,
expand_modifier, rtx_def**)
/data/repos/gcc/pristine/gcc/expr.c:10006
0x6fb505 expand_expr
/data/repos/gcc/pristine/gcc/expr.h:444
0x6fb505 expand_expr_real_1(tree_node*, rtx_def*, machine_mode,
expand_modifier, rtx_def**)
/data/repos/gcc/pristine/gcc/expr.c:9614
0x6fb623 expand_expr_real_1(tree_node*, rtx_def*, machine_mode,
expand_modifier, rtx_def**)
/data/repos/gcc/pristine/gcc/expr.c:9179
0x9152a8 expand_expr
/data/repos/gcc/pristine/gcc/expr.h:444
0x9152a8 expand_return(tree_node*)
/data/repos/gcc/pristine/gcc/stmt.c:1546
0x635273 expand_gimple_stmt_1
/data/repos/gcc/pristine/gcc/cfgexpand.c:2082
0x635273 expand_gimple_stmt
/data/repos/gcc/pristine/gcc/cfgexpand.c:2204
0x636c82 expand_gimple_basic_block
/data/repos/gcc/pristine/gcc/cfgexpand.c:3978
0x639aee gimple_expand_cfg
/data/repos/gcc/pristine/gcc/cfgexpand.c:4497
