match.pd: Optimize __builtin_mul_overflow_p (x, cst, (stype)0) [PR105…

…777] The following patch is an incremental change to the PR30314 enhancement, this one handles signed types. For signed types (but still, the same for 1st and result element type and non-zero constant that fits into that type), we actually need to watch for overflow in direction to positive and negative infinity and it also depends on whether the cst operand is positive or negative. For __builtin_mul_overflow_p (x, cst, (stype) 0): For cst > 0, we can simplify it to: x > INT_MAX / cst || x < INT_MIN / cst aka: x + (unsigned) (INT_MIN / cst) > (unsigned) (INT_MAX / cst) - (unsigned) (INT_MIN / cst) and for cst < 0 to: x < INT_MAX / cst || x > INT_MIN / cst aka: x + (unsigned) (INT_MAX / cst) > (unsigned) (INT_MIN / cst) - (unsigned) (INT_MAX / cst) Additionally, I've added executable testcases, so we don't just check for the optimization to be performed, but also that it is correct (done that even for the other PR's testcase). 2022-06-03 Jakub Jelinek <[email protected]> PR middle-end/30314 PR middle-end/105777 * match.pd (__builtin_mul_overflow_p (x, cst, (stype) 0) -> x > stype_max / cst || x < stype_min / cst): New simplification. * gcc.dg/tree-ssa/pr30314.c: Add noipa attribute to all functions. * gcc.dg/tree-ssa/pr105777.c: New test. * gcc.c-torture/execute/pr30314.c: New test. * gcc.c-torture/execute/pr105777.c: New test.
jwakely · Jun 3, 2022 · 1982fe2 · 1982fe2
1 parent 0fd3c70
commit 1982fe2
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Showing 5 changed files with 201 additions and 7 deletions.
diff --git a/gcc/match.pd b/gcc/match.pd
@@ -5970,15 +5970,39 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
    (ovf @1 @0))))
 
 /* Optimize __builtin_mul_overflow_p (x, cst, (utype) 0) if all 3 types
-   are unsigned to x > (umax / cst).  */
+   are unsigned to x > (umax / cst).  Similarly for signed type, but
+   in that case it needs to be outside of a range.  */
 (simplify
  (imagpart (IFN_MUL_OVERFLOW:cs@2 @0 integer_nonzerop@1))
   (if (INTEGRAL_TYPE_P (TREE_TYPE (@0))
-       && TYPE_UNSIGNED (TREE_TYPE (@0))
        && TYPE_MAX_VALUE (TREE_TYPE (@0))
        && types_match (TREE_TYPE (@0), TREE_TYPE (TREE_TYPE (@2)))
        && int_fits_type_p (@1, TREE_TYPE (@0)))
-   (convert (gt @0 (trunc_div! { TYPE_MAX_VALUE (TREE_TYPE (@0)); } @1)))))
+   (if (TYPE_UNSIGNED (TREE_TYPE (@0)))
+    (convert (gt @0 (trunc_div! { TYPE_MAX_VALUE (TREE_TYPE (@0)); } @1)))
+    (if (TYPE_MIN_VALUE (TREE_TYPE (@0)))
+     (if (integer_minus_onep (@1))
+      (convert (eq @0 { TYPE_MIN_VALUE (TREE_TYPE (@0)); }))
+      (with
+       {
+	 tree lo = int_const_binop (TRUNC_DIV_EXPR,
+				    TYPE_MIN_VALUE (TREE_TYPE (@0)),
+				    fold_convert (TREE_TYPE (@0), @1));
+	 tree hi = int_const_binop (TRUNC_DIV_EXPR,
+				    TYPE_MAX_VALUE (TREE_TYPE (@0)),
+				    fold_convert (TREE_TYPE (@0), @1));
+	 tree etype = range_check_type (TREE_TYPE (@0));
+	 if (etype)
+	   {
+	     if (wi::neg_p (wi::to_wide (@1)))
+	       std::swap (lo, hi);
+	     lo = fold_convert (etype, lo);
+	     hi = fold_convert (etype, hi);
+	     hi = int_const_binop (MINUS_EXPR, hi, lo);
+	   }
+       }
+       (if (etype)
+        (convert (gt (minus (convert:etype @0) { lo; }) { hi; })))))))))
 
 /* Simplification of math builtins.  These rules must all be optimizations
    as well as IL simplifications.  If there is a possibility that the new

diff --git a/gcc/testsuite/gcc.c-torture/execute/pr105777.c b/gcc/testsuite/gcc.c-torture/execute/pr105777.c
@@ -0,0 +1,73 @@
+/* PR middle-end/105777 */
+
+#include "../../gcc.dg/tree-ssa/pr105777.c"
+
+int
+main ()
+{
+  if (foo (0) != 0
+      || foo (__INT_MAX__ / 35) != 0
+      || foo (__INT_MAX__ / 35 + 1) != 1
+      || foo (__INT_MAX__) != 1
+      || foo ((-__INT_MAX__ - 1) / 35) != 0
+      || foo ((-__INT_MAX__ - 1) / 35 - 1) != 1
+      || foo (-__INT_MAX__ - 1) != 1)
+    __builtin_abort ();
+  if (bar (0) != 0
+      || bar (__LONG_MAX__ / 35) != 0
+      || bar (__LONG_MAX__ / 35 + 1) != 1
+      || bar (__LONG_MAX__) != 1
+      || bar ((-__LONG_MAX__ - 1) / 35) != 0
+      || bar ((-__LONG_MAX__ - 1) / 35 - 1) != 1
+      || bar (-__LONG_MAX__ - 1) != 1)
+    __builtin_abort ();
+  if (baz (0) != 0
+      || baz (__INT_MAX__ / 42) != 0
+      || baz (__INT_MAX__ / 42 + 1) != 1
+      || baz (__INT_MAX__) != 1
+      || baz ((-__INT_MAX__ - 1) / 42) != 0
+      || baz ((-__INT_MAX__ - 1) / 42 - 1) != 1
+      || baz (-__INT_MAX__ - 1) != 1)
+    __builtin_abort ();
+  if (qux (0) != 0
+      || qux (__LONG_MAX__ / 42) != 0
+      || qux (__LONG_MAX__ / 42 + 1) != 1
+      || qux (__LONG_MAX__) != 1
+      || qux ((-__LONG_MAX__ - 1) / 42) != 0
+      || qux ((-__LONG_MAX__ - 1) / 42 - 1) != 1
+      || qux (-__LONG_MAX__ - 1) != 1)
+    __builtin_abort ();
+  if (corge (0) != 0
+      || corge (__INT_MAX__ / -39) != 0
+      || corge (__INT_MAX__ / -39 - 1) != 1
+      || corge (__INT_MAX__) != 1
+      || corge ((-__INT_MAX__ - 1) / -39) != 0
+      || corge ((-__INT_MAX__ - 1) / -39 + 1) != 1
+      || corge (-__INT_MAX__ - 1) != 1)
+    __builtin_abort ();
+  if (garply (0) != 0
+      || garply (__LONG_MAX__ / -39) != 0
+      || garply (__LONG_MAX__ / -39 - 1) != 1
+      || garply (__LONG_MAX__) != 1
+      || garply ((-__LONG_MAX__ - 1) / -39) != 0
+      || garply ((-__LONG_MAX__ - 1) / -39 + 1) != 1
+      || garply (-__LONG_MAX__ - 1) != 1)
+    __builtin_abort ();
+  if (grault (0) != 0
+      || grault (__INT_MAX__ / -46) != 0
+      || grault (__INT_MAX__ / -46 - 1) != 1
+      || grault (__INT_MAX__) != 1
+      || grault ((-__INT_MAX__ - 1) / -46) != 0
+      || grault ((-__INT_MAX__ - 1) / -46 + 1) != 1
+      || grault (-__INT_MAX__ - 1) != 1)
+    __builtin_abort ();
+  if (waldo (0) != 0
+      || waldo (__LONG_MAX__ / -46) != 0
+      || waldo (__LONG_MAX__ / -46 - 1) != 1
+      || waldo (__LONG_MAX__) != 1
+      || waldo ((-__LONG_MAX__ - 1) / -46) != 0
+      || waldo ((-__LONG_MAX__ - 1) / -46 + 1) != 1
+      || waldo (-__LONG_MAX__ - 1) != 1)
+    __builtin_abort ();
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.c-torture/execute/pr30314.c b/gcc/testsuite/gcc.c-torture/execute/pr30314.c
@@ -0,0 +1,29 @@
+/* PR middle-end/30314 */
+
+#include "../../gcc.dg/tree-ssa/pr30314.c"
+
+int
+main ()
+{
+  if (foo (0) != 0
+      || foo (~0U / 35) != 0
+      || foo (~0U / 35 + 1) != 1
+      || foo (~0U) != 1)
+    __builtin_abort ();
+  if (bar (0) != 0
+      || bar (~0UL / 35) != 0
+      || bar (~0UL / 35 + 1) != 1
+      || bar (~0UL) != 1)
+    __builtin_abort ();
+  if (baz (0) != 0
+      || baz (~0U / 42) != 0
+      || baz (~0U / 42 + 1) != 1
+      || baz (~0U) != 1)
+    __builtin_abort ();
+  if (qux (0) != 0
+      || qux (~0UL / 42) != 0
+      || qux (~0UL / 42 + 1) != 1
+      || qux (~0UL) != 1)
+    __builtin_abort ();
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr105777.c b/gcc/testsuite/gcc.dg/tree-ssa/pr105777.c
@@ -0,0 +1,68 @@
+/* PR middle-end/105777 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+/* { dg-final { scan-tree-dump-not "\.MUL_OVERFLOW " "optimized" } } */
+/* { dg-final { scan-tree-dump " \\+ 61356675;" "optimized" { target int32 } } } */
+/* { dg-final { scan-tree-dump " > 122713350" "optimized" { target int32 } } } */
+/* { dg-final { scan-tree-dump " \\+ 263524915338707880" "optimized" { target lp64 } } } */
+/* { dg-final { scan-tree-dump " > 527049830677415760" "optimized" { target lp64 } } } */
+/* { dg-final { scan-tree-dump " \\+ 51130563" "optimized" { target int32 } } } */
+/* { dg-final { scan-tree-dump " > 102261126" "optimized" { target int32 } } } */
+/* { dg-final { scan-tree-dump " \\+ 219604096115589900" "optimized" { target lp64 } } } */
+/* { dg-final { scan-tree-dump " > 439208192231179800" "optimized" { target lp64 } } } */
+/* { dg-final { scan-tree-dump " \\+ 55063683;" "optimized" { target int32 } } } */
+/* { dg-final { scan-tree-dump " > 110127366" "optimized" { target int32 } } } */
+/* { dg-final { scan-tree-dump " \\+ 236496718893712200" "optimized" { target lp64 } } } */
+/* { dg-final { scan-tree-dump " > 472993437787424400" "optimized" { target lp64 } } } */
+/* { dg-final { scan-tree-dump " \\+ 46684427" "optimized" { target int32 } } } */
+/* { dg-final { scan-tree-dump " > 93368854" "optimized" { target int32 } } } */
+/* { dg-final { scan-tree-dump " \\+ 200508087757712517" "optimized" { target lp64 } } } */
+/* { dg-final { scan-tree-dump " > 401016175515425034" "optimized" { target lp64 } } } */
+
+__attribute__((noipa)) int
+foo (int x)
+{
+  return __builtin_mul_overflow_p (x, 35, 0);
+}
+
+__attribute__((noipa)) int
+bar (long int x)
+{
+  return __builtin_mul_overflow_p (x, 35L, 0L);
+}
+
+__attribute__((noipa)) int
+baz (int x)
+{
+  return __builtin_mul_overflow_p (42, x, 0);
+}
+
+__attribute__((noipa)) int
+qux (long int x)
+{
+  return __builtin_mul_overflow_p (42, x, 0L);
+}
+
+__attribute__((noipa)) int
+corge (int x)
+{
+  return __builtin_mul_overflow_p (x, -39, 0);
+}
+
+__attribute__((noipa)) int
+garply (long int x)
+{
+  return __builtin_mul_overflow_p (x, -39L, 0L);
+}
+
+__attribute__((noipa)) int
+grault (int x)
+{
+  return __builtin_mul_overflow_p (-46, x, 0);
+}
+
+__attribute__((noipa)) int
+waldo (long int x)
+{
+  return __builtin_mul_overflow_p (-46, x, 0L);
+}
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr30314.c b/gcc/testsuite/gcc.dg/tree-ssa/pr30314.c
@@ -7,25 +7,25 @@
 /* { dg-final { scan-tree-dump " > 102261126" "optimized" { target int32 } } } */
 /* { dg-final { scan-tree-dump " > 439208192231179800" "optimized" { target lp64 } } } */
 
-int
+__attribute__((noipa)) int
 foo (unsigned int x)
 {
   return __builtin_mul_overflow_p (x, 35U, 0U);
 }
 
-int
+__attribute__((noipa)) int
 bar (unsigned long int x)
 {
   return __builtin_mul_overflow_p (x, 35UL, 0UL);
 }
 
-int
+__attribute__((noipa)) int
 baz (unsigned int x)
 {
   return __builtin_mul_overflow_p (42, x, 0U);
 }
 
-int
+__attribute__((noipa)) int
 qux (unsigned long int x)
 {
   return __builtin_mul_overflow_p (42, x, 0UL);