https://gcc.gnu.org/g:0bbdffc5d4f723f6a41b713519b156ea46ce5fc8
commit r15-7974-g0bbdffc5d4f723f6a41b713519b156ea46ce5fc8
Author: Andrew Pinski <quic_apin...@quicinc.com>
Date: Mon Mar 10 23:10:01 2025 -0700
aarch64: Fix DFP constants [PR119131]
After r15-6660-g45d306a835cb3f865, in some cases
DFP constants would cause an ICE. This is due to
do a mismatch of a few things. The predicate of the move
uses aarch64_valid_fp_move to say if the constant is valid or not.
But after reload/LRA when can_create_pseudo_p returns false;
aarch64_valid_fp_move
would return false for constants that were valid for the constraints
of the instruction. A strictor predicate compared to the constraint is
wrong.
In this case `Uvi` is the constraint while aarch64_valid_fp_move allows it
via aarch64_can_const_movi_rtx_p for !DECIMAL_FLOAT_MODE_P, there is no
such check
for DECIMAL_FLOAT_MODE_P.
The fix is to remove the check !DECIMAL_FLOAT_MODE_P in
aarch64_valid_fp_move
and in the define_expand. As now the predicate allows a superset of what is
allowed
by the constraints.
aarch64_float_const_representable_p should be rejecting DFP modes as they
can't be used
with instructions like `mov s0, 1.0`.
Changes since v1:
* v2: Add check to aarch64_float_const_representable_p for DFP.
Built and tested on aarch64-linux-gnu with no regressions.
PR target/119131
gcc/ChangeLog:
* config/aarch64/aarch64.cc (aarch64_valid_fp_move): Remove check
for !DECIMAL_FLOAT_MODE_P.
(aarch64_float_const_representable_p): Reject decimal floating
modes.
* config/aarch64/aarch64.md (mov<mode>): Likewise.
gcc/testsuite/ChangeLog:
* gcc.dg/torture/pr119131-1.c: New test.
Signed-off-by: Andrew Pinski <quic_apin...@quicinc.com>
Diff:
---
gcc/config/aarch64/aarch64.cc | 21 +++++++++++----------
gcc/config/aarch64/aarch64.md | 3 +--
gcc/testsuite/gcc.dg/torture/pr119131-1.c | 31 +++++++++++++++++++++++++++++++
3 files changed, 43 insertions(+), 12 deletions(-)
diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc
index 36b65df50c57..41054b54b383 100644
--- a/gcc/config/aarch64/aarch64.cc
+++ b/gcc/config/aarch64/aarch64.cc
@@ -11328,17 +11328,14 @@ aarch64_valid_fp_move (rtx dst, rtx src, machine_mode
mode)
if (MEM_P (src))
return true;
- if (!DECIMAL_FLOAT_MODE_P (mode))
- {
- if (aarch64_can_const_movi_rtx_p (src, mode)
- || aarch64_float_const_representable_p (src)
- || aarch64_float_const_zero_rtx_p (src))
- return true;
+ if (aarch64_can_const_movi_rtx_p (src, mode)
+ || aarch64_float_const_representable_p (src)
+ || aarch64_float_const_zero_rtx_p (src))
+ return true;
- /* Block FP immediates which are split during expand. */
- if (aarch64_float_const_rtx_p (src))
- return false;
- }
+ /* Block FP immediates which are split during expand. */
+ if (aarch64_float_const_rtx_p (src))
+ return false;
return can_create_pseudo_p ();
}
@@ -25611,6 +25608,10 @@ aarch64_float_const_representable_p (rtx x)
{
x = unwrap_const_vec_duplicate (x);
machine_mode mode = GET_MODE (x);
+
+ if (DECIMAL_FLOAT_MODE_P (mode))
+ return false;
+
if (!CONST_DOUBLE_P (x))
return false;
diff --git a/gcc/config/aarch64/aarch64.md b/gcc/config/aarch64/aarch64.md
index 03188a64ab17..031e621c98a1 100644
--- a/gcc/config/aarch64/aarch64.md
+++ b/gcc/config/aarch64/aarch64.md
@@ -1762,8 +1762,7 @@
&& aarch64_float_const_zero_rtx_p (operands[1])))
operands[1] = force_reg (<MODE>mode, operands[1]);
- if (!DECIMAL_FLOAT_MODE_P (<MODE>mode)
- && GET_CODE (operands[1]) == CONST_DOUBLE
+ if (GET_CODE (operands[1]) == CONST_DOUBLE
&& can_create_pseudo_p ()
&& !aarch64_can_const_movi_rtx_p (operands[1], <MODE>mode)
&& !aarch64_float_const_representable_p (operands[1])
diff --git a/gcc/testsuite/gcc.dg/torture/pr119131-1.c
b/gcc/testsuite/gcc.dg/torture/pr119131-1.c
new file mode 100644
index 000000000000..c62f702f98c1
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr119131-1.c
@@ -0,0 +1,31 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target dfp } */
+/* PR target/119131 */
+
+typedef __attribute__((__vector_size__ (64))) char C;
+typedef __attribute__((__vector_size__ (64))) _Decimal32 D;
+int a, b;
+_Decimal32 f;
+C e;
+C c;
+
+void
+foo (D d)
+{
+ d -= *(_Decimal32 *) __builtin_memset (&f, 0, 4);
+ b += a;
+ if (a)
+ b /= 0; /* { dg-warning "division by zero" } */
+ c = (C) d + e;
+}
+
+void
+foo1 (D d)
+{
+ __builtin_memset (&f, 0, 4);
+ d -= *(_Decimal32 *)&f;
+ b += a;
+ if (a)
+ b /= 0;/* { dg-warning "division by zero" } */
+ c = (C) d + e;
+}
