[gcc r14-8519] aarch64: Avoid allocating FPRs to address registers [PR113623]
Richard Sandiford
rsandifo@gcc.gnu.org
Tue Jan 30 09:30:54 GMT 2024
https://gcc.gnu.org/g:fa2739ac1b74769d97fba34db9b9a8aa8786539e
commit r14-8519-gfa2739ac1b74769d97fba34db9b9a8aa8786539e
Author: Richard Sandiford <richard.sandiford@arm.com>
Date: Tue Jan 30 09:30:35 2024 +0000
aarch64: Avoid allocating FPRs to address registers [PR113623]
For something like:
void
foo (void)
{
int *ptr;
asm volatile ("%0" : "=w" (ptr));
asm volatile ("%0" :: "m" (*ptr));
}
early-ra would allocate ptr to an FPR for the first asm, thus
leaving an FPR address in the second asm. The address was then
reloaded by LRA to make it valid.
But early-ra shouldn't be allocating at all in that kind of
situation. Doing so caused the ICE in the PR (with LDP fusion).
Fixed by making sure that we record address references as
GPR references.
gcc/
PR target/113623
* config/aarch64/aarch64-early-ra.cc (early_ra::preprocess_insns):
Mark all registers that occur in addresses as needing a GPR.
gcc/testsuite/
PR target/113623
* gcc.c-torture/compile/pr113623.c: New test.
Diff:
---
gcc/config/aarch64/aarch64-early-ra.cc | 9 ++
gcc/testsuite/gcc.c-torture/compile/pr113623.c | 137 +++++++++++++++++++++++++
2 files changed, 146 insertions(+)
diff --git a/gcc/config/aarch64/aarch64-early-ra.cc b/gcc/config/aarch64/aarch64-early-ra.cc
index 028296639b83..1a03d86e94b9 100644
--- a/gcc/config/aarch64/aarch64-early-ra.cc
+++ b/gcc/config/aarch64/aarch64-early-ra.cc
@@ -1173,6 +1173,15 @@ early_ra::preprocess_insns ()
if (!NONDEBUG_INSN_P (insn))
continue;
+ // Mark all registers that occur in addresses as needing a GPR.
+ vec_rtx_properties properties;
+ properties.add_insn (insn, true);
+ for (rtx_obj_reference ref : properties.refs ())
+ if (ref.is_reg ()
+ && ref.in_address ()
+ && !HARD_REGISTER_NUM_P (ref.regno))
+ m_pseudo_regs[ref.regno].flags |= ALLOWS_NONFPR | NEEDS_NONFPR;
+
if (GET_CODE (PATTERN (insn)) == USE
|| GET_CODE (PATTERN (insn)) == CLOBBER)
continue;
diff --git a/gcc/testsuite/gcc.c-torture/compile/pr113623.c b/gcc/testsuite/gcc.c-torture/compile/pr113623.c
new file mode 100644
index 000000000000..ed33890054ef
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/pr113623.c
@@ -0,0 +1,137 @@
+typedef struct A A;
+typedef struct B B;
+struct A { char *a; long b; };
+enum { C, D };
+typedef struct { A *c; A *d; } E;
+typedef enum { F } G;
+typedef enum { H } I;
+struct B { A *e, *f, *g, *h; char i; } j;
+int k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z, aa, ab, ac, ad, ae, af;
+int ag, ah, ai, aj, ak, al, am, an, ao, ap;
+E aq;
+G ar;
+I as;
+char at;
+
+static int
+foo (char *c, long d)
+{
+ switch (d) {
+ case 7:
+ switch (c[6])
+ case 'd':
+ if (ao)
+ case 'h':
+ if (an)
+ case 'r':
+ if (am)
+ case 's':
+ if (al)
+ if (ak)
+ return C;
+ /* FALLTHRU */
+ case 8:
+ switch (c[7])
+ case 'e':
+ if (aj)
+ case 'h':
+ if (ai)
+ case 'n':
+ if (ah)
+ case 'y':
+ if (ag)
+ case 9:
+ switch (c[8])
+ case 'l':
+ case 0:
+ switch (c[9])
+ case 'e':
+ if (af)
+ if (ae)
+ case 'n':
+ if (ad)
+ case 't':
+ if (ac)
+ case 'y':
+ if (ab)
+ case 1:
+ switch (c[0])
+ case 'r':
+ case 2:
+ switch (c[1])
+ case 'e':
+ case 3:
+ switch (c[2])
+ case 'd':
+ if (aa)
+ case 'e':
+ if (z)
+ case 'h':
+ if (y)
+ case 'l':
+ if (x)
+ case 'n':
+ if (w)
+ case 's':
+ if (v)
+ case 4:
+ switch (c[3])
+ case 'h':
+ if (u)
+ case 't':
+ if (t)
+ case 5:
+ switch (c[4])
+ case 'e':
+ if (s)
+ case 'g':
+ if (r)
+ case 6:
+ switch (c[5])
+ case 'e':
+ if (q)
+ if (p)
+ case 'g':
+ if (o)
+ case 'n':
+ if (n)
+ if (m)
+ case 7:
+ switch (c[6])
+ case 'e':
+ if (l)
+ case 'g':
+ if (k)
+ return D;
+ }
+ return 0;
+}
+
+void bar (void);
+
+static int
+baz (B *x)
+{
+ aq.c = x->e;
+ aq.d = x->f;
+ ap = foo (x->e->a, x->e->b);
+ if (x->i)
+ bar ();
+ x->g = aq.c;
+ x->h = aq.d;
+ return 0;
+}
+
+void
+qux (void)
+{
+ for (; at;)
+ switch (as)
+ {
+ case H:
+ baz (&j);
+ j.f->b = 0;
+ if (ar)
+ baz (&j);
+ }
+}
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