Several libffi testcases and gcc.c-torture/execute/pr23135.c
fail with the execution error for sh4-unknown-linux-gnu after
the patch:
r128957 | zadeck | 2007-10-02 22:10:07 +0900 (Tue, 02 Oct 2007) | 70 lines
A reduced testcase is
typedef struct A {
unsigned long long a;
unsigned char b;
} A;
typedef struct B {
struct A x;
unsigned char y;
} B;
B B_fn(struct A b0, struct B b1)
{
struct B result;
result.x.a = b0.a + b1.x.a;
result.x.b = b0.b + b1.x.b + b1.y;
result.y = b0.b + b1.x.b;
printf("%d %d %d %d %d: %d %d %d\n", (int)b0.a, b0.b,
(int)b1.x.a, b1.x.b, b1.y,
(int)result.x.a, result.x.b, result.y);
return result;
}
which is compiled to
B_fn:
mov.l r8,@-r15
clrt
mov.l r9,@-r15
mov.l r10,@-r15
mov.l r11,@-r15
mov.l r12,@-r15
mov.l r13,@-r15
mov r2,r13
mov.l r14,@-r15
sts.l pr,@-r15
add #-28,r15
mov r15,r14
mov r14,r1
add #60,r1
mov.l @r1+,r7
mov.l @r1+,r8
add #-20,r15
mov.b @r1,r0
extu.b r6,r8
with -O2 -ml -m4 on sh-elf. The last extu.b instruction
clobbers r8 whose content was loaded from a memory with
"mov.l @r1+,r8".
The corresponding .lreg dump is:
(insn:HI 20 68 23 3 str3.c:12 (set (reg:DI 164 [ b1$x$a ])
(mem/s/c:DI (post_inc:SI (reg/f:SI 178)) [5 b1.x.a+0 S8 A32])) 186
{*movdi_i} (expr_list:REG_INC (reg/f:SI 178)
(nil)))
(insn:HI 23 20 19 3 str3.c:12 (set (reg:QI 179 [ b1.x.b ])
(mem/s/c:QI (reg/f:SI 178) [0 b1.x.b+0 S1 A32])) 182 {movqi_i}
(expr_list:REG_DEAD (reg/f:SI 178)
(nil)))
(insn:HI 19 23 76 3 str3.c:12 (set (reg:SI 165 [ b0$b ])
(zero_extend:SI (reg:QI 6 r6))) 153 {*zero_extendqisi2_compact} (nil))
and the .greg dump is:
(insn:HI 20 68 23 2 str3.c:12 (set (reg:DI 7 r7 [orig:164 b1$x$a ] [164])
(mem/s/c:DI (post_inc:SI (reg/f:SI 1 r1 [178])) [5 b1.x.a+0 S8 A32]))
186 {*movdi_i} (expr_list:REG_INC (reg/f:SI 1 r1 [178])
(nil)))
(insn:HI 23 20 19 2 str3.c:12 (set (reg:QI 0 r0 [orig:179 b1.x.b ] [179])
(mem/s/c:QI (reg/f:SI 1 r1 [178]) [0 b1.x.b+0 S1 A32])) 182 {movqi_i}
(nil))
(insn:HI 19 23 79 2 str3.c:12 (set (reg:SI 8 r8 [orig:165 b0$b ] [165])
(zero_extend:SI (reg:QI 6 r6))) 153 {*zero_extendqisi2_compact} (nil))
It looks that the register allocater selects r8 for pseudo
165, but r8 is already allocated as a part of the register
pair r7..r8 which is allocated for pseudo 164.
--
Summary: [4.3 Regression] Wrong register allocation on SH
Product: gcc
Version: 4.3.0
Status: UNCONFIRMED
Keywords: wrong-code
Severity: normal
Priority: P3
Component: middle-end
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: kkojima at gcc dot gnu dot org
GCC target triplet: sh-elf
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33662
