Bootstrapped and regtested on s390x-redhat-linux. Ok for master?
When a long double is passed to an asm statement with a "+fvm"
constraint, a LRA loop occurs. This happens, because LRA chooses the
widest register class in this case (VEC_REGS), but the code generated
by s390_md_asm_adjust() always wants FP_REGS. Mismatching register
classes cause infinite reloading.
Fix by treating "fv" constraints as "v" in s390_md_asm_adjust().
gcc/ChangeLog:
* config/s390/s390.c (f_constraint_p): Treat "fv" constraints
as "v".
gcc/testsuite/ChangeLog:
* gcc.target/s390/vector/long-double-asm-fprvrmem.c: New test.
---
gcc/config/s390/s390.c | 12 ++++++++++--
.../s390/vector/long-double-asm-fprvrmem.c | 11 +++++++++++
2 files changed, 21 insertions(+), 2 deletions(-)
create mode 100644
gcc/testsuite/gcc.target/s390/vector/long-double-asm-fprvrmem.c
diff --git a/gcc/config/s390/s390.c b/gcc/config/s390/s390.c
index 151136bedbc..f7b1c03561e 100644
--- a/gcc/config/s390/s390.c
+++ b/gcc/config/s390/s390.c
@@ -16714,13 +16714,21 @@ s390_shift_truncation_mask (machine_mode mode)
static bool
f_constraint_p (const char *constraint)
{
+ bool seen_f_p = false;
+ bool seen_v_p = false;
+
for (size_t i = 0, c_len = strlen (constraint); i < c_len;
i += CONSTRAINT_LEN (constraint[i], constraint + i))
{
if (constraint[i] == 'f')
- return true;
+ seen_f_p = true;
+ if (constraint[i] == 'v')
+ seen_v_p = true;
}
- return false;
+
+ /* Treat "fv" constraints as "v", because LRA will choose the widest register
+ * class. */
+ return seen_f_p && !seen_v_p;
}
/* Implement TARGET_MD_ASM_ADJUST hook in order to fix up "f"
diff --git a/gcc/testsuite/gcc.target/s390/vector/long-double-asm-fprvrmem.c
b/gcc/testsuite/gcc.target/s390/vector/long-double-asm-fprvrmem.c
new file mode 100644
index 00000000000..f95656c5723
--- /dev/null
+++ b/gcc/testsuite/gcc.target/s390/vector/long-double-asm-fprvrmem.c
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-options "-O3 -march=z14 -mzarch" } */
+
+long double
+foo (long double x)
+{
+ x = x * x;
+ asm("# %0" : "+fvm"(x));
+ x = x + x;
+ return x;
+}
--
2.29.2
