aix: align double complex

AIX word-aligns floating point doubles.  This behavior also extends to
double _Complex, which had been overlooked when compiler support for
double _Complex was added.

This patch adds DCmode to the modes whose alignment is adjusted and
adds a testcase to confirm the correct alignment.

gcc/ChangeLog:

2021-03-10  David Edelsohn  <dje.gcc@gmail.com>

	PR target/99492
	* config/rs6000/aix.h (ADJUST_FIELD_ALIGN): Add check for DCmode.
	* config/rs6000/rs6000.c (rs6000_special_round_type_align): Same.

gcc/testsuite/ChangeLog:

2021-03-10  David Edelsohn  <dje.gcc@gmail.com>

	PR target/99492
	* gcc.target/powerpc/pr99492.c: New testcase.
This commit is contained in:
David Edelsohn 2021-03-09 17:52:36 -05:00
parent 8c21bc6646
commit 4fa6356be1
3 changed files with 54 additions and 2 deletions

View File

@ -224,7 +224,8 @@
/* AIX word-aligns FP doubles but doubleword-aligns 64-bit ints. */
#define ADJUST_FIELD_ALIGN(FIELD, TYPE, COMPUTED) \
((TARGET_ALIGN_NATURAL == 0 \
&& TYPE_MODE (strip_array_types (TYPE)) == DFmode) \
&& (TYPE_MODE (strip_array_types (TYPE)) == DFmode \
|| TYPE_MODE (strip_array_types (TYPE)) == DCmode)) \
? MIN ((COMPUTED), 32) \
: (COMPUTED))

View File

@ -7855,7 +7855,8 @@ rs6000_special_round_type_align (tree type, unsigned int computed,
while (TREE_CODE (type) == ARRAY_TYPE)
type = TREE_TYPE (type);
if (type != error_mark_node && TYPE_MODE (type) == DFmode)
if (type != error_mark_node
&& (TYPE_MODE (type) == DFmode || TYPE_MODE (type) == DCmode))
align = MAX (align, 64);
}

View File

@ -0,0 +1,50 @@
/* { dg-do run { target { powerpc*-ibm-aix* } } } */
/* { dg-options "" } */
void abort (void);
struct A {
double _Complex a[64];
};
struct B {
double b[64];
};
struct C {
char c1;
double _Complex c2;
};
struct D {
char c1;
double c2;
};
int main() {
if (__alignof(double _Complex) != 8)
abort();
if (__alignof(struct A) != 8)
abort;
if (__alignof(struct C) != 4)
abort;
if (__builtin_offsetof(struct C, c2) != 4)
abort();
if (__alignof(double) != 8)
abort();
if (__alignof(struct B) != 8)
abort();
if (__alignof(struct D) != 4)
abort();
if (__builtin_offsetof(struct D, c2) != 4)
abort();
return 0;
}