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[PR99123] inline-asm: Don't use decompose_mem_address to find used hard regs

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Inline asm in question has empty constraint which means anything
including memory with invalid address.  To check used hard regs we
used decompose_mem_address which assumes memory with valid address.
The patch implements the same semantics without assuming valid
addresses.

gcc/ChangeLog:

	PR inline-asm/99123
	* lra-constraints.c (uses_hard_regs_p): Don't use decompose_mem_address.

gcc/testsuite/ChangeLog:

	PR inline-asm/99123
	* gcc.target/i386/pr99123.c: New.
This commit is contained in:
Vladimir N. Makarov 2021-02-24 13:54:10 -05:00
parent 8265ab07f3
commit b6680c2084
2 changed files with 51 additions and 10 deletions
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10
gcc/lra-constraints.c
View File

@ -1904,16 +1904,6 @@ uses_hard_regs_p (rtx x, HARD_REG_SET set)
return (x_hard_regno >= 0
&& overlaps_hard_reg_set_p (set, mode, x_hard_regno));
}
if (MEM_P (x))
{
struct address_info ad;
decompose_mem_address (&ad, x);
if (ad.base_term != NULL && uses_hard_regs_p (*ad.base_term, set))
return true;
if (ad.index_term != NULL && uses_hard_regs_p (*ad.index_term, set))
return true;
}
fmt = GET_RTX_FORMAT (code);
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
{

51
gcc/testsuite/gcc.target/i386/pr99123.c Normal file
View File

@ -0,0 +1,51 @@
/* { dg-do compile } */
/* { dg-options "-O2" } */
static inline void *
baz (void *s, unsigned long c, unsigned int count)
{
int d0, d1;
__asm__ __volatile__ (""
: "=&c" (d0), "=&D" (d1)
:"a" (c), "q" (count), "0" (count / 4), "" ((long) s) /// "1"
:"memory");
return s;
}
struct A
{
unsigned long *a;
};
inline static void *
bar (struct A *x, int y)
{
char *ptr;
ptr = (void *) x->a[y >> 12];
ptr += y % (1UL << 12);
return (void *) ptr;
}
int
foo (struct A *x, unsigned int *y, int z, int u)
{
int a, b, c, d, e;
z += *y;
c = z + u;
a = (z >> 12) + 1;
do
{
b = (a << 12);
d = b - z;
e = c - z;
if (e < d)
d = e;
baz (bar (x, z), 0, d);
z = b;
a++;
}
while (z < c);
return 0;
}