Hi!
The following testcase ICEs, because the temp_stmts were removed in
wrong order, from the ones appearing earlier in the IL to the later ones,
so insert_debug_temps_for_defs can reintroduce dead SSA_NAMEs back into the
IL.
The following patch fixes that by removing them in the order they were
pushed into the vector, which is from later ones to earlier ones.
Additionally, I've noticed I forgot to call release_defs on the removed
stmts.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2023-11-11 Jakub Jelinek <ja...@redhat.com>
PR middle-end/112430
* tree-ssa-math-opts.cc (match_uaddc_usubc): Remove temp_stmts in the
order they were pushed rather than in reverse order. Call
release_defs after gsi_remove.
* gcc.dg/pr112430.c: New test.
--- gcc/tree-ssa-math-opts.cc.jj 2023-11-02 07:49:20.699815089 +0100
+++ gcc/tree-ssa-math-opts.cc 2023-11-10 13:43:13.059912310 +0100
@@ -5047,11 +5047,11 @@ match_uaddc_usubc (gimple_stmt_iterator
gsi_insert_before (gsi, g, GSI_SAME_STMT);
/* Remove some further statements which can't be kept in the IL because
they can use SSA_NAMEs whose setter is going to be removed too. */
- while (temp_stmts.length ())
+ for (gimple *g2 : temp_stmts)
{
- g = temp_stmts.pop ();
- gsi2 = gsi_for_stmt (g);
+ gsi2 = gsi_for_stmt (g2);
gsi_remove (&gsi2, true);
+ release_defs (g2);
}
}
else
@@ -5068,10 +5068,12 @@ match_uaddc_usubc (gimple_stmt_iterator
rhs1 = gimple_assign_rhs1 (g);
gsi2 = gsi_for_stmt (g);
gsi_remove (&gsi2, true);
+ release_defs (g);
}
gcc_checking_assert (rhs1 == gimple_assign_lhs (im2));
gsi2 = gsi_for_stmt (im2);
gsi_remove (&gsi2, true);
+ release_defs (im2);
/* Replace the re2 statement with __real__ of the newly added
.UADDC/.USUBC call. */
if (re2)
--- gcc/testsuite/gcc.dg/pr112430.c.jj 2023-11-10 13:45:18.707163791 +0100
+++ gcc/testsuite/gcc.dg/pr112430.c 2023-11-10 13:45:04.523361174 +0100
@@ -0,0 +1,30 @@
+/* PR middle-end/112430 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -g" } */
+
+int a, b, c, d, e;
+unsigned int f;
+
+static void
+foo (unsigned int x)
+{
+ unsigned int g = x < c;
+ int h = f < b;
+ x += h;
+ g += x < h;
+ f = x;
+ x = g;
+ g = f += a;
+ h = f < a;
+ x += h;
+ c += f < d;
+ x += c;
+ g += x < c;
+ e = g;
+}
+
+void
+bar (unsigned int x)
+{
+ foo (x);
+}
Jakub
