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From: Jakub Jelinek <jakub@redhat.com>
To: Richard Biener <rguenther@suse.de>
Cc: Jeff Law <jeffreyalaw@gmail.com>, gcc-patches@gcc.gnu.org
Subject: Re: [PATCH] match.pd: Optimize __builtin_mul_overflow_p (x, cst, (stype)0) [PR105777]
Date: Fri, 3 Jun 2022 11:49:41 +0200	[thread overview]
Message-ID: <YpnY9bhlHUL3Gaxe@tucnak> (raw)
In-Reply-To: <nycvar.YFH.7.77.849.2206021346170.32424@jbgna.fhfr.qr>

On Thu, Jun 02, 2022 at 01:46:25PM +0000, Richard Biener wrote:
> > Starting x86_64-linux and i686-linux bootstrap/regtest, ok for trunk if
> > it passes them?
> 
> OK.

Testing found one special case that wasn't handled correctly in the patch,
when @1 is -1, INT_MIN / -1 during the lo computation overflows and in the
end it resulted in __builtin_mul_overflow_p (x, -1, 0) being always 0.
The correct test is x == INT_MIN though.

Here is the slightly adjusted testcase (just addition of
      (if (integer_minus_onep (@1))
       (convert (eq @0 { TYPE_MIN_VALUE (TREE_TYPE (@0)); }))
and one ) and some reindentation), which I've now committed.

Thanks.

2022-06-03  Jakub Jelinek  <jakub@redhat.com>

	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.

--- gcc/match.pd.jj	2022-06-01 17:54:30.536372912 +0200
+++ gcc/match.pd	2022-06-03 09:16:39.872567123 +0200
@@ -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
--- gcc/testsuite/gcc.dg/tree-ssa/pr30314.c.jj	2022-06-02 11:17:23.689835550 +0200
+++ gcc/testsuite/gcc.dg/tree-ssa/pr30314.c	2022-06-02 14:23:19.294093445 +0200
@@ -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);
--- gcc/testsuite/gcc.dg/tree-ssa/pr105777.c.jj	2022-06-02 14:22:57.017328731 +0200
+++ gcc/testsuite/gcc.dg/tree-ssa/pr105777.c	2022-06-02 14:19:29.399521503 +0200
@@ -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);
+}
--- gcc/testsuite/gcc.c-torture/execute/pr30314.c.jj	2022-06-02 14:32:30.070276332 +0200
+++ gcc/testsuite/gcc.c-torture/execute/pr30314.c	2022-06-02 14:32:22.121360286 +0200
@@ -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;
+}
--- gcc/testsuite/gcc.c-torture/execute/pr105777.c.jj	2022-06-02 14:32:50.287062810 +0200
+++ gcc/testsuite/gcc.c-torture/execute/pr105777.c	2022-06-02 14:38:36.289409212 +0200
@@ -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;
+}


	Jakub


      reply	other threads:[~2022-06-03  9:51 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-06-02 13:11 Jakub Jelinek
2022-06-02 13:46 ` Richard Biener
2022-06-03  9:49   ` Jakub Jelinek [this message]

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