rs6000: Use rs6000_emit_move in movmisalign<mode> expander [PR104681]

The following testcase ICEs, because for some strange reason it decides to use
movmisaligntf during expansion where the destination is MEM and source is
CONST_DOUBLE.  For normal mov<mode> expanders the rs6000 backend uses
rs6000_emit_move to ensure that if one operand is a MEM, the other is a REG
and a few other things, but for movmisalign<mode> nothing enforced this.
The middle-end documents that movmisalign<mode> shouldn't fail, so we can't
force that through predicates or condition on the expander.

2022-02-25  Jakub Jelinek  <jakub@redhat.com>

	PR target/104681
	* config/rs6000/vector.md (movmisalign<mode>): Use rs6000_emit_move.

	* g++.dg/opt/pr104681.C: New test.

diff --git a/gcc/config/rs6000/vector.md b/gcc/config/rs6000/vector.md
index b87a742..4d0797c 100644 (file)
--- a/gcc/config/rs6000/vector.md
+++ b/gcc/config/rs6000/vector.md
@@ -1519,7 +1519,10 @@
  [(set (match_operand:VEC_N 0 "nonimmediate_operand")
        (match_operand:VEC_N 1 "any_operand"))]
  "VECTOR_MEM_VSX_P (<MODE>mode) && TARGET_ALLOW_MOVMISALIGN"
- "")
+{
+  rs6000_emit_move (operands[0], operands[1], <MODE>mode);
+  DONE;
+})
 
 ;; Vector shift right in bits. Currently supported ony for shift
 ;; amounts that can be expressed as byte shifts (divisible by 8).

diff --git a/gcc/testsuite/g++.dg/opt/pr104681.C b/gcc/testsuite/g++.dg/opt/pr104681.C
new file mode 100644 (file)
index 0000000..ea54940
--- /dev/null
+++ b/gcc/testsuite/g++.dg/opt/pr104681.C
@@ -0,0 +1,19 @@
+// PR target/104681
+// { dg-do compile }
+// { dg-options "-O2" }
+
+void bar ();
+struct A {
+  A (bool) : a(7.0L), b(0) {}
+  long double a;
+  long b;
+};
+struct B {
+  void foo () { c = bar; }
+  A c;
+};
+struct C {
+  void baz ();
+  B d;
+};
+void C::baz () { d.foo (); }