[PATCH] arm: Fix arm {,u}subvdi4 and usubvsi4 expanders [PR94286]

[Jakub Jelinek via Gcc-patches]

Hi!

The following testcase ICEs, because these expanders will happily create
a SImode 0x80000000 CONST_INT, which is not valid RTL, as CONST_INTs need to
be sign extended from the mode precision to full HWI.

Fixed thusly, bootstrapped/regtested on armv7hl-linux-gnueabi, ok for trunk?

2020-03-24  Jakub Jelinek  <ja...@redhat.com>

        PR target/94286
        * config/arm/arm.md (subvdi4, usubvsi4, usubvdi4): Use gen_int_mode
        instead of GEN_INT.

        * gcc.dg/pr94286.c: New test.

--- gcc/config/arm/arm.md.jj    2020-03-20 09:32:48.094338574 +0100
+++ gcc/config/arm/arm.md       2020-03-23 19:23:18.263211430 +0100
@@ -1481,7 +1481,7 @@ (define_expand "subvdi4"
     lo_op2 = force_reg (SImode, lo_op2);
   if (CONST_INT_P (lo_op2))
     emit_insn (gen_cmpsi2_addneg (lo_result, lo_op1, lo_op2,
-                                 GEN_INT (-INTVAL (lo_op2))));
+                                 gen_int_mode (-INTVAL (lo_op2), SImode)));
   else
     emit_insn (gen_subsi3_compare1 (lo_result, lo_op1, lo_op2));
 
@@ -1525,7 +1525,8 @@ (define_expand "usubvsi4"
     }
   else if (CONST_INT_P (operands[2]))
     emit_insn (gen_cmpsi2_addneg (operands[0], operands[1], operands[2],
-                                 GEN_INT (-INTVAL (operands[2]))));
+                                 gen_int_mode (-INTVAL (operands[2]),
+                                               SImode)));
   else if (CONST_INT_P (operands[1]))
     {
       mode = CC_RSBmode;
@@ -1597,7 +1598,7 @@ (define_expand "usubvdi4"
     lo_op2 = force_reg (SImode, lo_op2);
   if (CONST_INT_P (lo_op2))
     emit_insn (gen_cmpsi2_addneg (lo_result, lo_op1, lo_op2,
-                                 GEN_INT (-INTVAL (lo_op2))));
+                                 gen_int_mode (-INTVAL (lo_op2), SImode)));
   else
     emit_insn (gen_subsi3_compare1 (lo_result, lo_op1, lo_op2));
 
--- gcc/testsuite/gcc.dg/pr94286.c.jj   2020-03-23 19:24:26.294207928 +0100
+++ gcc/testsuite/gcc.dg/pr94286.c      2020-03-23 19:21:32.501771489 +0100
@@ -0,0 +1,11 @@
+/* PR target/94286 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -g" } */
+
+unsigned a, b;
+
+int
+foo (void)
+{
+  return __builtin_sub_overflow (a, 0x80000000U, &b);
+}

        Jakub