From b3d8d88efa4d8467d3b0657cc8a4a3e1913d939c Mon Sep 17 00:00:00 2001
From: Martin Sebor <msebor@redhat.com>
Date: Fri, 16 Jun 2017 20:52:03 +0000
Subject: [PATCH] PR tree-optimization/80934 - bzero should be assumed not to
escape pointer argument
PR tree-optimization/80934 - bzero should be assumed not to escape pointer argument
PR tree-optimization/80933 - redundant bzero/bcopy calls not eliminated
gcc/ChangeLog:
PR tree-optimization/80933
PR tree-optimization/80934
* builtins.c (fold_builtin_3): Do not handle bcmp here.
* gimple-fold.c (gimple_fold_builtin_bcmp): New function.
(gimple_fold_builtin_bcopy, gimple_fold_builtin_bzero): Likewise.
(gimple_fold_builtin): Call them.
gcc/testsuite/ChangeLog:
PR tree-optimization/80933
PR tree-optimization/80934
* gcc.dg/fold-bcopy.c: New test.
* gcc.dg/tree-ssa/ssa-dse-30.c: Likewise..
* gcc.dg/tree-ssa/alias-36.c: Likewise.
* gcc/testsuite/gcc.dg/pr79214.c: Adjust.
* gcc.dg/tree-prof/val-prof-7.c: Likewise.
* gcc.dg/Wsizeof-pointer-memaccess1.c: Likewise.
* gcc.dg/builtins-nonnull.c: Likewise.
From-SVN: r249278
---
gcc/ChangeLog | 9 ++
gcc/builtins.c | 1 -
gcc/gimple-fold.c | 88 +++++++++++++++++--
gcc/testsuite/ChangeLog | 12 +++
.../gcc.dg/Wsizeof-pointer-memaccess1.c | 2 +-
gcc/testsuite/gcc.dg/builtins-nonnull.c | 5 +-
gcc/testsuite/gcc.dg/fold-bcopy.c | 54 ++++++++++++
gcc/testsuite/gcc.dg/pr79214.c | 2 +-
gcc/testsuite/gcc.dg/tree-prof/val-prof-7.c | 13 +--
gcc/testsuite/gcc.dg/tree-ssa/alias-36.c | 28 ++++++
gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-30.c | 31 +++++++
11 files changed, 224 insertions(+), 21 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/fold-bcopy.c
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/alias-36.c
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-30.c
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index dfabe1752578..f8412afc58f4 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+2017-06-16 Martin Sebor <msebor@redhat.com>
+
+ PR tree-optimization/80933
+ PR tree-optimization/80934
+ * builtins.c (fold_builtin_3): Do not handle bcmp here.
+ * gimple-fold.c (gimple_fold_builtin_bcmp): New function.
+ (gimple_fold_builtin_bcopy, gimple_fold_builtin_bzero): Likewise.
+ (gimple_fold_builtin): Call them.
+
2017-06-16 Jan Hubicka <hubicka@ucw.cz>
* gimple-ssa-isolate-paths.c (isolate_path): Set edge leading to path
diff --git a/gcc/builtins.c b/gcc/builtins.c
index 30462ad0f419..ce657bf9e30a 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -9034,7 +9034,6 @@ fold_builtin_3 (location_t loc, tree fndecl,
return do_mpfr_remquo (arg0, arg1, arg2);
break;
- case BUILT_IN_BCMP:
case BUILT_IN_MEMCMP:
return fold_builtin_memcmp (loc, arg0, arg1, arg2);;
diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c
index 0f8e326a0e84..a00c2c88713b 100644
--- a/gcc/gimple-fold.c
+++ b/gcc/gimple-fold.c
@@ -1077,6 +1077,83 @@ done:
return true;
}
+/* Transform a call to built-in bcmp(a, b, len) at *GSI into one
+ to built-in memcmp (a, b, len). */
+
+static bool
+gimple_fold_builtin_bcmp (gimple_stmt_iterator *gsi)
+{
+ tree fn = builtin_decl_implicit (BUILT_IN_MEMCMP);
+
+ if (!fn)
+ return false;
+
+ /* Transform bcmp (a, b, len) into memcmp (a, b, len). */
+
+ gimple *stmt = gsi_stmt (*gsi);
+ tree a = gimple_call_arg (stmt, 0);
+ tree b = gimple_call_arg (stmt, 1);
+ tree len = gimple_call_arg (stmt, 2);
+
+ gimple *repl = gimple_build_call (fn, 3, a, b, len);
+ replace_call_with_call_and_fold (gsi, repl);
+
+ return true;
+}
+
+/* Transform a call to built-in bcopy (src, dest, len) at *GSI into one
+ to built-in memmove (dest, src, len). */
+
+static bool
+gimple_fold_builtin_bcopy (gimple_stmt_iterator *gsi)
+{
+ tree fn = builtin_decl_implicit (BUILT_IN_MEMMOVE);
+
+ if (!fn)
+ return false;
+
+ /* bcopy has been removed from POSIX in Issue 7 but Issue 6 specifies
+ it's quivalent to memmove (not memcpy). Transform bcopy (src, dest,
+ len) into memmove (dest, src, len). */
+
+ gimple *stmt = gsi_stmt (*gsi);
+ tree src = gimple_call_arg (stmt, 0);
+ tree dest = gimple_call_arg (stmt, 1);
+ tree len = gimple_call_arg (stmt, 2);
+
+ gimple *repl = gimple_build_call (fn, 3, dest, src, len);
+ gimple_call_set_fntype (as_a <gcall *> (stmt), TREE_TYPE (fn));
+ replace_call_with_call_and_fold (gsi, repl);
+
+ return true;
+}
+
+/* Transform a call to built-in bzero (dest, len) at *GSI into one
+ to built-in memset (dest, 0, len). */
+
+static bool
+gimple_fold_builtin_bzero (gimple_stmt_iterator *gsi)
+{
+ tree fn = builtin_decl_implicit (BUILT_IN_MEMSET);
+
+ if (!fn)
+ return false;
+
+ /* Transform bzero (dest, len) into memset (dest, 0, len). */
+
+ gimple *stmt = gsi_stmt (*gsi);
+ tree dest = gimple_call_arg (stmt, 0);
+ tree len = gimple_call_arg (stmt, 1);
+
+ gimple_seq seq = NULL;
+ gimple *repl = gimple_build_call (fn, 3, dest, integer_zero_node, len);
+ gimple_seq_add_stmt_without_update (&seq, repl);
+ gsi_replace_with_seq_vops (gsi, seq);
+ fold_stmt (gsi);
+
+ return true;
+}
+
/* Fold function call to builtin memset or bzero at *GSI setting the
memory of size LEN to VAL. Return whether a simplification was made. */
@@ -3288,16 +3365,17 @@ gimple_fold_builtin (gimple_stmt_iterator *gsi)
enum built_in_function fcode = DECL_FUNCTION_CODE (callee);
switch (fcode)
{
+ case BUILT_IN_BCMP:
+ return gimple_fold_builtin_bcmp (gsi);
+ case BUILT_IN_BCOPY:
+ return gimple_fold_builtin_bcopy (gsi);
case BUILT_IN_BZERO:
- return gimple_fold_builtin_memset (gsi, integer_zero_node,
- gimple_call_arg (stmt, 1));
+ return gimple_fold_builtin_bzero (gsi);
+
case BUILT_IN_MEMSET:
return gimple_fold_builtin_memset (gsi,
gimple_call_arg (stmt, 1),
gimple_call_arg (stmt, 2));
- case BUILT_IN_BCOPY:
- return gimple_fold_builtin_memory_op (gsi, gimple_call_arg (stmt, 1),
- gimple_call_arg (stmt, 0), 3);
case BUILT_IN_MEMCPY:
return gimple_fold_builtin_memory_op (gsi, gimple_call_arg (stmt, 0),
gimple_call_arg (stmt, 1), 0);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 84d81d36ceb1..962c3887c343 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,15 @@
+2017-06-16 Martin Sebor <msebor@redhat.com>
+
+ PR tree-optimization/80933
+ PR tree-optimization/80934
+ * gcc.dg/fold-bcopy.c: New test.
+ * gcc.dg/tree-ssa/ssa-dse-30.c: Likewise..
+ * gcc.dg/tree-ssa/alias-36.c: Likewise.
+ * gcc/testsuite/gcc.dg/pr79214.c: Adjust.
+ * gcc.dg/tree-prof/val-prof-7.c: Likewise.
+ * gcc.dg/Wsizeof-pointer-memaccess1.c: Likewise.
+ * gcc.dg/builtins-nonnull.c: Likewise.
+
2017-06-16 James Greenhalgh <james.greenhalgh@arm.com>
PR target/71778
diff --git a/gcc/testsuite/gcc.dg/Wsizeof-pointer-memaccess1.c b/gcc/testsuite/gcc.dg/Wsizeof-pointer-memaccess1.c
index 7feb122b553b..f4e8552918d2 100644
--- a/gcc/testsuite/gcc.dg/Wsizeof-pointer-memaccess1.c
+++ b/gcc/testsuite/gcc.dg/Wsizeof-pointer-memaccess1.c
@@ -1,6 +1,6 @@
/* Test -Wsizeof-pointer-memaccess warnings. */
/* { dg-do compile } */
-/* { dg-options "-Wall -Wno-sizeof-array-argument" } */
+/* { dg-options "-Wall -Wno-sizeof-array-argument -Wno-stringop-overflow" } */
/* { dg-require-effective-target alloca } */
typedef __SIZE_TYPE__ size_t;
diff --git a/gcc/testsuite/gcc.dg/builtins-nonnull.c b/gcc/testsuite/gcc.dg/builtins-nonnull.c
index fa9eaf2327df..726f8e199da3 100644
--- a/gcc/testsuite/gcc.dg/builtins-nonnull.c
+++ b/gcc/testsuite/gcc.dg/builtins-nonnull.c
@@ -24,8 +24,9 @@ void sink (int, ...);
void test_memfuncs (void *s, unsigned n)
{
- /* Bzero is not declared attribute nonnull. */
- bzero (null (), n);
+ /* Bzero is not declared attribute nonnull (maybe it should be?)
+ but it's transformed into a call to memset() which is. */
+ bzero (null (), n); /* { dg-warning "argument 1 null where non-null expected" } */
T (memcpy (null (), s, n)); /* { dg-warning "argument 1 null where non-null expected" } */
T (memcpy (s, null (), n)); /* { dg-warning "argument 2 null where non-null expected" } */
diff --git a/gcc/testsuite/gcc.dg/fold-bcopy.c b/gcc/testsuite/gcc.dg/fold-bcopy.c
new file mode 100644
index 000000000000..ed6cd0603392
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/fold-bcopy.c
@@ -0,0 +1,54 @@
+/* PR tree-optimization/80933 - redundant bzero/bcopy calls not eliminated
+ { dg-do compile }
+ { dg-options "-O0 -Wall -fdump-tree-gimple" } */
+
+void f0 (void *dst, const void *src, unsigned n)
+{
+ /* Bcopy(src, dst, ...) corresponds to memmove(dst, src, ...),
+ with the first two arguments transposed, not memcpy. */
+ __builtin_bcopy (src, dst, n);
+}
+
+void f1 (void *p, const void *q, unsigned n)
+{
+ /* A call with zero size should be eliminated. */
+ __builtin_bcopy (q, p, 0);
+}
+
+int f2 (const void *p, const void *q, unsigned n)
+{
+ return __builtin_bcmp (p, q, n);
+}
+
+int f3 (const void *p, const void *q)
+{
+ /* A call with zero size should be folded into 0. */
+ return __builtin_bcmp (p, q, 0);
+}
+
+int f4 (const void *p, unsigned n)
+{
+ /* A call with the same argument should also be folded into 0. */
+ return __builtin_bcmp (p, p, n);
+}
+
+void f5 (void *p, unsigned n)
+{
+ __builtin_bzero (p, n);
+}
+
+void f6 (void *p)
+{
+ /* A call with zero size should be eliminated. */
+ __builtin_bzero (p, 0);
+}
+
+/* Verify that calls to bcmp, bcopy, and bzero have all been removed
+ and one of each replaced with memcmp, memmove, and memset, respectively.
+ The remaining three should be eliminated.
+ { dg-final { scan-tree-dump-not "bcmp|bcopy|bzero" "gimple" } }
+ { dg-final { scan-tree-dump-times "memcmp|memmove|memset" 3 "gimple" } }
+
+ Verify that the bcopy to memmove transformation correctly transposed
+ the source and destination pointer arguments.
+ { dg-final { scan-tree-dump-times "memmove \\(dst, src" 1 "gimple" } } */
diff --git a/gcc/testsuite/gcc.dg/pr79214.c b/gcc/testsuite/gcc.dg/pr79214.c
index 79d2a2569569..6cf254fb28d9 100644
--- a/gcc/testsuite/gcc.dg/pr79214.c
+++ b/gcc/testsuite/gcc.dg/pr79214.c
@@ -22,7 +22,7 @@ size_t range (void)
void test_bzero (void)
{
- bzero (d, range ()); /* { dg-warning ".__builtin_bzero. writing 4 or more bytes into a region of size 3 overflows the destination" } */
+ bzero (d, range ()); /* { dg-warning ".__builtin_(bzero|memset). writing 4 or more bytes into a region of size 3 overflows the destination" } */
}
void test_memcpy (void)
diff --git a/gcc/testsuite/gcc.dg/tree-prof/val-prof-7.c b/gcc/testsuite/gcc.dg/tree-prof/val-prof-7.c
index 84ec9fbf7b57..5a4e77712e30 100644
--- a/gcc/testsuite/gcc.dg/tree-prof/val-prof-7.c
+++ b/gcc/testsuite/gcc.dg/tree-prof/val-prof-7.c
@@ -4,14 +4,10 @@
char *buffer1;
char *buffer2;
+/* Bzero is not tested because it gets transformed into memset. */
+
#define DEFINE_TEST(N) \
__attribute__((noinline)) \
-void bzero_test_ ## N (int len) \
-{ \
- __builtin_bzero (buffer1, len); \
-} \
- \
-__attribute__((noinline)) \
void memcpy_test_ ## N (int len) \
{ \
__builtin_memcpy (buffer1, buffer2, len); \
@@ -31,7 +27,6 @@ void memset_test_ ## N (int len) \
\
void test_stringops_ ## N(int len) \
{ \
- bzero_test_ ## N (len); \
memcpy_test_## N (len); \
mempcpy_test_ ## N (len); \
memset_test_ ## N (len); \
@@ -64,10 +59,6 @@ int main() {
return 0;
}
-/* { dg-final-use-not-autofdo { scan-ipa-dump "Single value 8 stringop transformation on __builtin_bzero" "profile" } } */
-/* { dg-final-use-not-autofdo { scan-ipa-dump "Single value 55 stringop transformation on __builtin_bzero" "profile" } } */
-/* { dg-final-use-not-autofdo { scan-ipa-dump-times "Single value 32 stringop transformation on __builtin_bzero" 0 "profile" } } */
-
/* { dg-final-use-not-autofdo { scan-ipa-dump "Single value 8 stringop transformation on __builtin_memcpy" "profile" } } */
/* { dg-final-use-not-autofdo { scan-ipa-dump "Single value 55 stringop transformation on __builtin_memcpy" "profile" } } */
/* { dg-final-use-not-autofdo { scan-ipa-dump-times "Single value 32 stringop transformation on __builtin_memcpy" 0 "profile" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/alias-36.c b/gcc/testsuite/gcc.dg/tree-ssa/alias-36.c
new file mode 100644
index 000000000000..61b601a229eb
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/alias-36.c
@@ -0,0 +1,28 @@
+/* PR tree-optimization/80934 - bzero should be assumed not to escape
+ pointer argument
+ { dg-do compile }
+ { dg-options "-O2 -fdump-tree-alias" } */
+
+void foobar (void);
+
+void f (void);
+
+void g (void)
+{
+ char d[32];
+ __builtin_memset (d, 0, sizeof d);
+ f ();
+ if (*d != 0)
+ foobar ();
+}
+
+void h (void)
+{
+ char d[32];
+ __builtin_bzero (d, sizeof d);
+ f ();
+ if (*d != 0)
+ foobar ();
+}
+
+/* { dg-final { scan-tree-dump-not "memset|foobar|bzero" "alias" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-30.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-30.c
new file mode 100644
index 000000000000..ece8cb2a80ca
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-30.c
@@ -0,0 +1,31 @@
+/* PR tree-optimization/80933 - redundant bzero/bcopy calls not eliminated
+ { dg-do compile }
+ { dg-options "-O2 -fdump-tree-dse1" } */
+
+void sink (void*);
+
+void test_bcopy (const void *s)
+{
+ char d[33];
+
+ /* Bcopy is transformed into memcpy and those calls are expanded
+ inline in EVRP, before DSE runs, so this test doesn't actually
+ verify that DSE does its job. */
+ __builtin_bcopy (s, d, sizeof d);
+ __builtin_bcopy (s, d, sizeof d);
+
+ sink (d);
+}
+
+void test_bzero (void)
+{
+ char d[33];
+
+ __builtin_bzero (d, sizeof d);
+ __builtin_bzero (d, sizeof d);
+
+ sink (d);
+}
+
+/* { dg-final { scan-tree-dump-times "builtin_memset" 1 "dse1" } } */
+/* { dg-final { scan-tree-dump-not "builtin_(bcopy|bzero|memcpy)" "dse1" } } */
--
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