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re PR target/46779 ([avr] wrong code generation for values held in R28/R29)

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PR target/46779
	PR target/45291
	PR target/41894
	* gcc.target/avr/pr46779-1.c: New test case
	* gcc.target/avr/pr46779-2.c: New test case

From-SVN: r172442
This commit is contained in:
Georg-Johann Lay 2011-04-14 18:50:02 +00:00 committed by Georg-Johann Lay
parent 81c1113ac9
commit 54578a5777
3 changed files with 110 additions and 0 deletions
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8
gcc/testsuite/ChangeLog
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@ -1,3 +1,11 @@
2011-04-14 Georg-Johann Lay <avr@gjlay.de>
PR target/46779
PR target/45291
PR target/41894
* gcc.target/avr/pr46779-1.c: New test case
* gcc.target/avr/pr46779-2.c: New test case
2011-04-14 Jason Merrill <jason@redhat.com>
* g++.dg/cpp0x/sfinae15.C: New.

51
gcc/testsuite/gcc.target/avr/pr46779-1.c Normal file
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/* { dg-do run } */
/* { dg-options "-Os -fsplit-wide-types" } */
/* This testcase should uncover bugs like
PR46779
PR45291
PR41894
The inline asm just serves to direct y into the Y register.
Otherwise, it is hard to write a "stable" test case that
also fails with slight variations in source code, middle- resp.
backend.
The problem is that Y is also the frame-pointer, and
avr.c:avr_hard_regno_mode_ok disallows QI to get in Y-reg.
However, the y.a = 0 generates a
(set (subreg:QI (reg:HI pseudo)) ...)
where pseudo gets allocated to Y.
Reload fails to generate the right spill.
*/
#include <stdlib.h>
struct S
{
unsigned char a, b;
} ab = {12, 34};
void yoo (struct S y)
{
__asm volatile ("ldi %B0, 56" : "+y" (y));
y.a = 0;
__asm volatile ("; y = %0" : "+y" (y));
ab = y;
}
int main ()
{
yoo (ab);
if (ab.a != 0)
abort();
if (ab.b != 56)
abort();
exit (0);
return 0;
}

51
gcc/testsuite/gcc.target/avr/pr46779-2.c Normal file
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@ -0,0 +1,51 @@
/* { dg-do run } */
/* { dg-options "-Os -fno-split-wide-types" } */
/* This testcase should uncover bugs like
PR46779
PR45291
PR41894
The inline asm just serves to direct y into the Y register.
Otherwise, it is hard to write a "stable" test case that
also fails with slight variations in source code, middle- resp.
backend.
The problem is that Y is also the frame-pointer, and
avr.c:avr_hard_regno_mode_ok disallows QI to get in Y-reg.
However, the y.a = 0 generates a
(set (subreg:QI (reg:HI pseudo)) ...)
where pseudo gets allocated to Y.
Reload fails to generate the right spill.
*/
#include <stdlib.h>
struct S
{
unsigned char a, b;
} ab = {12, 34};
void yoo (struct S y)
{
__asm volatile ("ldi %B0, 56" : "+y" (y));
y.a = 0;
__asm volatile ("; y = %0" : "+y" (y));
ab = y;
}
int main ()
{
yoo (ab);
if (ab.a != 0)
abort();
if (ab.b != 56)
abort();
exit (0);
return 0;
}