https://gcc.gnu.org/g:8ad57623b394796b3dd2a8f22d7535df430cb53d
commit 8ad57623b394796b3dd2a8f22d7535df430cb53d
Author: Jeff Law <j...@ventanamicro.com>
Date: Wed May 7 15:06:58 2025 -0600
[RISC-V][PR target/120137][PR target/120154] Don't create out-of-range
permutation constants
To make hashing sensible we canonicalize constant vectors in the hash table
so
that their first entry always has the value zero. That normalization can
result in a value that can't be represented in the element mode.
So before entering anything into the hash table we need to verify the
normalized entries will fit into the element's mode.
This fixes both 120137 and its duplicate 120154. This has been tested in my
tester. I'm just waiting for the pre-commit tester to render its verdict.
PR target/120137
PR target/120154
gcc/
* config/riscv/riscv-vect-permconst.cc (process_bb): Verify each
canonicalized element fits into the vector element mode.
gcc/testsuite/
* gcc.target/riscv/pr120137.c: New test.
* gcc.target/riscv/pr120154.c: New test.
(cherry picked from commit 49c44911df72f55e2004ffa9f5eb362de29ca188)
Diff:
---
gcc/config/riscv/riscv-vect-permconst.cc | 20 +++++++++++++++++++-
gcc/testsuite/gcc.target/riscv/pr120137.c | 12 ++++++++++++
gcc/testsuite/gcc.target/riscv/pr120154.c | 22 ++++++++++++++++++++++
3 files changed, 53 insertions(+), 1 deletion(-)
diff --git a/gcc/config/riscv/riscv-vect-permconst.cc
b/gcc/config/riscv/riscv-vect-permconst.cc
index feecc7ed6da0..8e13cf8d5587 100644
--- a/gcc/config/riscv/riscv-vect-permconst.cc
+++ b/gcc/config/riscv/riscv-vect-permconst.cc
@@ -203,6 +203,24 @@ vector_permconst::process_bb (basic_block bb)
if (bias < 0 || bias > 16384 / 8)
continue;
+ /* We need to verify that each element would be a valid value
+ in the inner mode after applying the bias. */
+ machine_mode inner = GET_MODE_INNER (GET_MODE (cvec));
+ HOST_WIDE_INT precision = GET_MODE_PRECISION (inner).to_constant ();
+ int i;
+ for (i = 0; i < CONST_VECTOR_NUNITS (cvec).to_constant (); i++)
+ {
+ HOST_WIDE_INT val = INTVAL (CONST_VECTOR_ELT (cvec, i)) - bias;
+ if (val != sext_hwi (val, precision))
+ break;
+ }
+
+ /* If the loop terminated early, then we found a case where the
+ adjusted constant would not fit, so we can't record the constant
+ for this case (it's unlikely to be useful anyway. */
+ if (i != CONST_VECTOR_NUNITS (cvec).to_constant ())
+ continue;
+
/* At this point we have a load of a constant integer vector from the
constant pool. That constant integer vector is hopefully a
permutation constant. We need to make a copy of the vector and
@@ -211,7 +229,7 @@ vector_permconst::process_bb (basic_block bb)
XXX This violates structure sharing conventions. */
rtvec_def *nvec = gen_rtvec (CONST_VECTOR_NUNITS (cvec).to_constant ());
- for (int i = 0; i < CONST_VECTOR_NUNITS (cvec).to_constant (); i++)
+ for (i = 0; i < CONST_VECTOR_NUNITS (cvec).to_constant (); i++)
nvec->elem[i] = GEN_INT (INTVAL (CONST_VECTOR_ELT (cvec, i)) - bias);
rtx copy = gen_rtx_CONST_VECTOR (GET_MODE (cvec), nvec);
diff --git a/gcc/testsuite/gcc.target/riscv/pr120137.c
b/gcc/testsuite/gcc.target/riscv/pr120137.c
new file mode 100644
index 000000000000..c55a1c1b5bf3
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/pr120137.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-march=rv64gcv_zvl256b -mrvv-vector-bits=zvl -mabi=lp64" } */
+
+char b[13][13];
+void c() {
+ for (int d = 0; d < 13; ++d)
+ for (int e = 0; e < 13; ++e)
+ b[d][e] = e == 0 ? -98 : 38;
+}
+
+
+
diff --git a/gcc/testsuite/gcc.target/riscv/pr120154.c
b/gcc/testsuite/gcc.target/riscv/pr120154.c
new file mode 100644
index 000000000000..fd849ca154ae
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/pr120154.c
@@ -0,0 +1,22 @@
+/* { dg-do compile } */
+/* { dg-options "-march=rv64gv -mabi=lp64" } */
+
+
+
+typedef __attribute__((__vector_size__(4))) char V;
+
+V g;
+
+V
+bar(V a, V b)
+{
+ V s = a + b + g;
+ return s;
+}
+
+V
+foo()
+{
+ return bar((V){20}, (V){23, 150});
+}
+
