The following fixes a missed valueization when simplifying
a MEM[&...] combination during valueization.
Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.
2021-11-12 Richard Biener <rguent...@suse.de>
PR tree-optimization/103204
* tree-ssa-sccvn.c (valueize_refs_1): Re-valueize the
top operand after folding in an address.
* gcc.dg/torture/pr103204.c: New testcase.
---
gcc/testsuite/gcc.dg/torture/pr103204.c | 16 ++++++++++++++++
gcc/tree-ssa-sccvn.c | 13 ++++++++-----
2 files changed, 24 insertions(+), 5 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/torture/pr103204.c
diff --git a/gcc/testsuite/gcc.dg/torture/pr103204.c
b/gcc/testsuite/gcc.dg/torture/pr103204.c
new file mode 100644
index 00000000000..b08b6864691
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr103204.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+
+int a[1][1];
+int b, c;
+void d()
+{
+ int e;
+ int f[0];
+ int *g;
+ for (; e;)
+ c = b;
+ if (a[0][b] = (__UINTPTR_TYPE__)f != 3)
+ g = &f[b];
+ int h;
+ *g = *g = *g = h;
+}
diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c
index 7be5d4e406f..149674e6a16 100644
--- a/gcc/tree-ssa-sccvn.c
+++ b/gcc/tree-ssa-sccvn.c
@@ -1640,13 +1640,12 @@ static void
valueize_refs_1 (vec<vn_reference_op_s> *orig, bool *valueized_anything,
bool with_avail = false)
{
- vn_reference_op_t vro;
- unsigned int i;
-
*valueized_anything = false;
- FOR_EACH_VEC_ELT (*orig, i, vro)
+ for (unsigned i = 0; i < orig->length (); ++i)
{
+re_valueize:
+ vn_reference_op_t vro = &(*orig)[i];
if (vro->opcode == SSA_NAME
|| (vro->op0 && TREE_CODE (vro->op0) == SSA_NAME))
{
@@ -1694,7 +1693,11 @@ valueize_refs_1 (vec<vn_reference_op_s> *orig, bool
*valueized_anything,
&& (*orig)[i - 1].opcode == MEM_REF)
{
if (vn_reference_maybe_forwprop_address (orig, &i))
- *valueized_anything = true;
+ {
+ *valueized_anything = true;
+ /* Re-valueize the current operand. */
+ goto re_valueize;
+ }
}
/* If it transforms a non-constant ARRAY_REF into a constant
one, adjust the constant offset. */
--
2.31.1
