3 files changed, 49 insertions, 2 deletions
diff --git a/gcc/match.pd b/gcc/match.pd
index f421c74..f920bc4 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -5587,6 +5587,21 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
    (with { tree t = TREE_TYPE (@0), cpx = build_complex_type (t); }
     (cmp (imagpart (IFN_MUL_OVERFLOW:cpx @0 @1)) { build_zero_cst (t); })))))
 
+/* Demote operands of IFN_{ADD,SUB,MUL}_OVERFLOW.  */
+(for ovf (IFN_ADD_OVERFLOW IFN_SUB_OVERFLOW IFN_MUL_OVERFLOW)
+ (simplify
+  (ovf (convert@2 @0) @1)
+  (if (INTEGRAL_TYPE_P (TREE_TYPE (@0))
+       && INTEGRAL_TYPE_P (TREE_TYPE (@2))
+       && TYPE_PRECISION (TREE_TYPE (@2)) > TYPE_PRECISION (TREE_TYPE (@0)))
+   (ovf @0 @1)))
+ (simplify
+  (ovf @1 (convert@2 @0))
+  (if (INTEGRAL_TYPE_P (TREE_TYPE (@0))
+       && INTEGRAL_TYPE_P (TREE_TYPE (@2))
+       && TYPE_PRECISION (TREE_TYPE (@2)) > TYPE_PRECISION (TREE_TYPE (@0)))
+   (ovf @1 @0))))
+
 /* Simplification of math builtins.  These rules must all be optimizations
    as well as IL simplifications.  If there is a possibility that the new
    form could be a pessimization, the rule should go in the canonicalization
diff --git a/gcc/testsuite/gcc.target/i386/pr97950.c b/gcc/testsuite/gcc.target/i386/pr97950.c
index 277311d..185d733 100644
--- a/gcc/testsuite/gcc.target/i386/pr97950.c
+++ b/gcc/testsuite/gcc.target/i386/pr97950.c
@@ -1,10 +1,10 @@
 /* PR target/95950 */
 /* { dg-do compile } */
 /* { dg-options "-O2 -mtune=generic" } */
-/* { dg-final { scan-assembler-times "\tseta\t" 4 } } */
+/* { dg-final { scan-assembler-times "\tset\[ab]\t" 4 } } */
 /* { dg-final { scan-assembler-times "\tseto\t" 16 } } */
 /* { dg-final { scan-assembler-times "\tsetc\t" 4 } } */
-/* { dg-final { scan-assembler-not "\tjn?a\t" } } */
+/* { dg-final { scan-assembler-not "\tjn?\[ab]\t" } } */
 /* { dg-final { scan-assembler-not "\tjn?o\t" } } */
 /* { dg-final { scan-assembler-not "\tjn?c\t" } } */
 
diff --git a/gcc/testsuite/gcc.target/i386/pr99591.c b/gcc/testsuite/gcc.target/i386/pr99591.c
new file mode 100644
index 0000000..01d8485
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr99591.c
@@ -0,0 +1,32 @@
+/* PR tree-optimization/99591 */
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+/* { dg-final { scan-assembler-not "\tmovs\[bw]l\t" } } */
+
+int
+foo (signed char a, signed char b)
+{
+  signed char r;
+  return __builtin_add_overflow (a, b, &r);
+}
+
+int
+bar (short a, short b)
+{
+  short r;
+  return __builtin_add_overflow (a, b, &r);
+}
+
+int
+baz (signed char a, signed char b)
+{
+  signed char r;
+  return __builtin_add_overflow ((int) a, (int) b, &r);
+}
+
+int
+qux (short a, short b)
+{
+  short r;
+  return __builtin_add_overflow ((int) a, (int) b, &r);
+}