[PR98722] LRA: Check that target has no 3-op add insn to transform 2 plus expression.

Patch cf2ac1c30af0fa783c8d72e527904dda5d8cc330 for solving PR97969 was
assumed for targets with absent 3-op add insn.  But the original patch did
not check this.  This patch adds the check.

gcc/ChangeLog:

	PR rtl-optimization/98722
	* lra-eliminations.c (eliminate_regs_in_insn): Check that target
	has no 3-op add insn to transform insns containing two pluses.

gcc/testsuite/ChangeLog:

	PR rtl-optimization/98722
	* g++.target/s390/pr98722.C: New.

diff --git a/gcc/lra-eliminations.c b/gcc/lra-eliminations.c
index ebcadd1006cee227008c8965c3ce40fe1066551d..5b9717574ed0621e995cf768fda917f375e57e88 100644 (file)
--- a/gcc/lra-eliminations.c
+++ b/gcc/lra-eliminations.c
@@ -1057,7 +1057,10 @@ eliminate_regs_in_insn (rtx_insn *insn, bool replace_p, bool first_p,
        reg2 = SUBREG_REG (reg2);
       if (REG_P (reg1) && REG_P (reg2)
          && REGNO (reg1) < FIRST_PSEUDO_REGISTER
-         && REGNO (reg2) >= FIRST_PSEUDO_REGISTER)
+         && REGNO (reg2) >= FIRST_PSEUDO_REGISTER
+         && GET_MODE (reg1) == Pmode
+         && !have_addptr3_insn (gen_reg_rtx (Pmode), reg1,
+                                XEXP (XEXP (SET_SRC (set), 0), 1)))
        {
          XEXP (XEXP (SET_SRC (set), 0), 0) = op2;
          XEXP (SET_SRC (set), 1) = op1;

diff --git a/gcc/testsuite/g++.target/s390/pr98722.C b/gcc/testsuite/g++.target/s390/pr98722.C
new file mode 100644 (file)
index 0000000..64edaf3
--- /dev/null
+++ b/gcc/testsuite/g++.target/s390/pr98722.C
@@ -0,0 +1,12 @@
+// { dg-do compile }
+// { dg-options "-Og -fno-tree-fre -fno-split-wide-types" }
+struct B {
+  virtual void Method();
+};
+typedef void (B::*fn_type_a)();
+
+int main() {
+  fn_type_a f(&B::Method);
+  B b;
+  (b.*f)();
+}