diff mbox

[PR70920] transform (intptr_t) x eq/ne CST to x eq/ne (typeof x) cst

Message ID CAAgBjM=7jXUBgeAz8DVfUVrqUTwLEiq-kH=cjkd6JtbTkDi9Fg@mail.gmail.com
State New
Headers show

Commit Message

Prathamesh Kulkarni July 25, 2016, 12:44 a.m. UTC 
Hi Richard,
The attached patch tries to fix PR70920.
It adds your pattern from comment 1 in the PR
(with additional gating on INTEGRAL_TYPE_P to avoid regressing finalize_18.f90)
and second pattern, which is reverse of the first transform.
I needed to update ssa-dom-branch-1.c because with patch applied,
jump threading removed the second if (i != 0B) block.
The dumps with and without patch for ssa-dom-branch-1.c start
to differ with forwprop1:

before:
 <bb 3>:
  _1 = temp_16(D)->code;
  _2 = _1 == 42;
  _3 = (int) _2;
  _4 = (long int) _3;
  temp_17 = (struct rtx_def *) _4;
  if (temp_17 != 0B)
    goto <bb 4>;
  else
    goto <bb 8>;

after:
<bb 3>:
  _1 = temp_16(D)->code;
  _2 = _1 == 42;
  _3 = (int) _2;
  _4 = (long int) _2;
  temp_17 = (struct rtx_def *) _4;
  if (_1 == 42)
    goto <bb 4>;
  else
    goto <bb 8>;

I suppose the transform is correct for above test-case ?

Then vrp dump shows:
 Threaded jump 5 --> 9 to 13
  Threaded jump 8 --> 9 to 13
  Threaded jump 3 --> 9 to 13
  Threaded jump 12 --> 9 to 14
Removing basic block 9
basic block 9, loop depth 0
 pred:
if (i1_10(D) != 0B)
  goto <bb 10>;
else
  goto <bb 11>;
 succ:       10
             11

So there remained two instances of if (i1_10 (D) != 0B) in dom2 dump file,
and hence needed to update the test-case.

Bootstrapped and tested on x86_64-unknown-linux-gnu.
OK to commit ?

PS: Writing changelog entries for match.pd is a bit tedious.
Should we add optional names for pattern so we can refer to them by names
in the ChangeLog for the more complicated ones ?
Or maybe just use comments:
(simplify /* name */ ... ) -;)

Thanks,
Prathamesh
diff mbox

Patch

diff --git a/gcc/match.pd b/gcc/match.pd
index 21bf617..7c736be 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -3408,3 +3408,23 @@  DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
 	 { CONSTRUCTOR_ELT (ctor, idx / k)->value; })
 	(BIT_FIELD_REF { CONSTRUCTOR_ELT (ctor, idx / k)->value; }
 		       @1 { bitsize_int ((idx % k) * width); })))))))))
+
+/* PR70920: Transform (intptr_t)x eq/ne CST to x eq/ne (typeof x) CST.  */
+
+(for cmp (ne eq)
+ (simplify
+  (cmp (convert@2 @0) INTEGER_CST@1)
+  (if (POINTER_TYPE_P (TREE_TYPE (@0))
+       && INTEGRAL_TYPE_P (TREE_TYPE (@2)))
+   (cmp @0 (convert @1)))))
+
+/* Reverse of the above case:
+   x has integral_type, CST is a pointer constant.
+   Transform (typeof CST)x eq/ne CST to x eq/ne (typeof x) CST.  */
+
+(for cmp (ne eq)
+ (simplify
+  (cmp (convert @0) @1)
+  (if (POINTER_TYPE_P (TREE_TYPE (@1))
+       && INTEGRAL_TYPE_P (TREE_TYPE (@0)))
+    (cmp @0 (convert @1)))))
diff --git a/gcc/testsuite/gcc.dg/pr70920-1.c b/gcc/testsuite/gcc.dg/pr70920-1.c
new file mode 100644
index 0000000..9b7e2d0
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr70920-1.c
@@ -0,0 +1,20 @@ 
+/* { dg-do compile } */
+/* { dg-options "-fdump-tree-gimple" } */
+
+#include <stdint.h>
+
+void f1();
+void f2();
+
+void
+foo (int *a)
+{
+  if ((intptr_t) a == 0)
+    {
+      f1 ();
+      if (a)
+	f2 (); 
+    }
+}
+
+/* { dg-final { scan-tree-dump "if \\(a == 0B\\)" "gimple" } } */
diff --git a/gcc/testsuite/gcc.dg/pr70920-2.c b/gcc/testsuite/gcc.dg/pr70920-2.c
new file mode 100644
index 0000000..2db9897
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr70920-2.c
@@ -0,0 +1,21 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-forwprop-details" } */
+
+#include <stdint.h>
+
+void f1();
+void f2();
+
+void
+foo (int *a)
+{
+  int cst = 0;
+  if ((intptr_t) a == cst)
+    {
+      f1 ();
+      if (a) 
+	f2 (); 
+    }
+}
+
+/* { dg-final { scan-tree-dump "gimple_simplified to if \\(a_\[0-9\]*\\(D\\) == 0B\\)" "forwprop1" } } */
diff --git a/gcc/testsuite/gcc.dg/pr70920-3.c b/gcc/testsuite/gcc.dg/pr70920-3.c
new file mode 100644
index 0000000..71e0d8d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr70920-3.c
@@ -0,0 +1,20 @@ 
+/* { dg-do compile } */
+/* { dg-options "-Wno-int-to-pointer-cast -fdump-tree-gimple" } */
+
+#include <stdint.h>
+
+void f1();
+void f2();
+
+void
+foo (int a)
+{
+  if ((int *) a == 0)
+    {
+      f1 ();
+      if (a)
+	f2 (); 
+    }
+}
+
+/* { dg-final { scan-tree-dump "if \\(a == 0\\)" "gimple" } } */
diff --git a/gcc/testsuite/gcc.dg/pr70920-4.c b/gcc/testsuite/gcc.dg/pr70920-4.c
new file mode 100644
index 0000000..f92c5a6
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr70920-4.c
@@ -0,0 +1,21 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-forwprop-details -Wno-int-to-pointer-cast" } */
+
+#include <stdint.h>
+
+void f1();
+void f2();
+
+void
+foo (int a)
+{
+  void *cst = 0; 
+  if ((int *) a == cst)
+    {
+      f1 ();
+      if (a) 
+	f2 (); 
+    }
+}
+
+/* { dg-final { scan-tree-dump "gimple_simplified to if \\(a_\[0-9\]*\\(D\\) == 0\\)" "forwprop1" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-dom-branch-1.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-dom-branch-1.c
index 18f9041..d38e3a8 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/ssa-dom-branch-1.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-dom-branch-1.c
@@ -21,7 +21,7 @@  try_combine (rtx i1, rtx newpat)
 
 /* There should be three tests against i1.  Two from the hash table
    dumps, one in the code itself.  */
-/* { dg-final { scan-tree-dump-times "if .i1_" 3 "dom2"} } */
+/* { dg-final { scan-tree-dump-times "if .i1_" 2 "dom2"} } */
 
 /* There should be no actual jump threads realized by DOM.  The
    legitimize jump threads are handled in VRP and those discovered