This patch changes the ranger VRP pass to simplify all statements, not
just the ones with ranges. I believe Jeff had mentioned we were no
longer doing this a while back. Now we need it when running as the VRP2
pass to satisfy the testcase: gcc.dg/wrapped-binop-simplify.c
This also requires a testcase adjustment since EVRP will now perform
this simplification, and it causes a test looking for it in VRP1 to
fail. In that test, I simply disable evrp, and then add a duplicate of
the test which then tests that EVRP also performs the optimization.
Bootstrapped on x86_64-pc-linux-gnu with no regressions. Pushed.
Andrew
>From cb153222404e2e149aa65a4b3139b09477551203 Mon Sep 17 00:00:00 2001
From: Andrew MacLeod <amacl...@redhat.com>
Date: Wed, 20 Oct 2021 13:37:29 -0400
Subject: [PATCH 1/2] Fold all statements in Ranger VRP.
Until now, ranger VRP has only simplified statements with ranges. This patch
enables us to fold all statements.
gcc/
* tree-vrp.c (rvrp_folder::fold_stmt): If simplification fails, try
to fold anyway.
gcc/testsuite/
* gcc.dg/tree-ssa/vrp98.c: Disable evrp for vrp1 test.
* gcc.dg/tree-ssa/vrp98-1.c: New. Test for folding in evrp.
---
gcc/testsuite/gcc.dg/tree-ssa/vrp98-1.c | 41 +++++++++++++++++++++++++
gcc/testsuite/gcc.dg/tree-ssa/vrp98.c | 2 +-
gcc/tree-vrp.c | 5 ++-
3 files changed, 46 insertions(+), 2 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/vrp98-1.c
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/vrp98-1.c b/gcc/testsuite/gcc.dg/tree-ssa/vrp98-1.c
new file mode 100644
index 00000000000..daa3f073b92
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/vrp98-1.c
@@ -0,0 +1,41 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target int128 } */
+/* { dg-options "-Os -fdump-tree-evrp-details" } */
+
+#include <stdint.h>
+#include <limits.h>
+
+typedef unsigned int word __attribute__((mode(word)));
+typedef unsigned __int128 bigger_than_word;
+
+int
+foo (bigger_than_word a, word b, uint8_t c)
+{
+ /* Must fold use of t1 into use of b, as b is no wider than word_mode. */
+ const uint8_t t1 = b % UCHAR_MAX;
+
+ /* Must NOT fold use of t2 into use of a, as a is wider than word_mode. */
+ const uint8_t t2 = a % UCHAR_MAX;
+
+ /* Must fold use of t3 into use of c, as c is narrower than t3. */
+ const uint32_t t3 = (const uint32_t)(c >> 1);
+
+ uint16_t ret = 0;
+
+ if (t1 == 1)
+ ret = 20;
+ else if (t2 == 2)
+ ret = 30;
+ else if (t3 == 3)
+ ret = 40;
+ /* Th extra condition below is necessary to prevent a prior pass from
+ folding away the cast. Ignored in scan-tree-dump. */
+ else if (t3 == 4)
+ ret = 50;
+
+ return ret;
+}
+
+/* { dg-final { scan-tree-dump "Folded into: if \\(_\[0-9\]+ == 1\\)" "evrp" } } */
+/* { dg-final { scan-tree-dump-not "Folded into: if \\(_\[0-9\]+ == 2\\)" "evrp" } } */
+/* { dg-final { scan-tree-dump "Folded into: if \\(_\[0-9\]+ == 3\\)" "evrp" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/vrp98.c b/gcc/testsuite/gcc.dg/tree-ssa/vrp98.c
index 982f091080c..78d3bbaf499 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/vrp98.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/vrp98.c
@@ -1,6 +1,6 @@
/* { dg-do compile } */
/* { dg-require-effective-target int128 } */
-/* { dg-options "-Os -fdump-tree-vrp1-details" } */
+/* { dg-options "-Os -fdisable-tree-evrp -fdump-tree-vrp1-details" } */
#include <stdint.h>
#include <limits.h>
diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index ba7a4efc7c6..a948c524098 100644
--- a/gcc/tree-vrp.c
+++ b/gcc/tree-vrp.c
@@ -50,6 +50,7 @@ along with GCC; see the file COPYING3. If not see
#include "gimple-range.h"
#include "gimple-range-path.h"
#include "value-pointer-equiv.h"
+#include "gimple-fold.h"
/* Set of SSA names found live during the RPO traversal of the function
for still active basic-blocks. */
@@ -4381,7 +4382,9 @@ public:
bool fold_stmt (gimple_stmt_iterator *gsi) OVERRIDE
{
- return m_simplifier.simplify (gsi);
+ if (m_simplifier.simplify (gsi))
+ return true;
+ return ::fold_stmt (gsi, follow_single_use_edges);
}
private:
--
2.17.2
