Hi,
I modified the patch so, that it always just converts two leafs of a
TRUTH(AND|OR)IF chain into a TRUTH_(AND|OR) expression, if branch costs are
high and leafs are simple without side-effects.
Additionally I added some testcases for it.
2011-10-06 Kai Tietz <kti...@redhat.com>
* fold-const.c (fold_truth_andor): Convert TRUTH_(AND|OR)IF_EXPR
to TRUTH_OR_EXPR, if suitable.
2011-10-06 Kai Tietz <kti...@redhat.com>
* gcc.dg/tree-ssa/ssa-ifbranch-1.c: New test.
* gcc.dg/tree-ssa/ssa-ifbranch-2.c: New test.
* gcc.dg/tree-ssa/ssa-ifbranch-3.c: New test.
* gcc.dg/tree-ssa/ssa-ifbranch-4.c: New test.
Bootstrapped and tested for all languages (including Ada and Obj-C++) on host
x86_64-unknown-linux-gnu. Ok for apply?
Regards,
Kai
Index: gcc-head/gcc/testsuite/gcc.dg/tree-ssa/ssa-ifbranch-1.c
===================================================================
--- /dev/null
+++ gcc-head/gcc/testsuite/gcc.dg/tree-ssa/ssa-ifbranch-1.c
@@ -0,0 +1,18 @@
+/* Skip on MIPS, S/390, and AVR due LOGICAL_OP_NON_SHORT_CIRCUIT, and
+ lower values in BRANCH_COST. */
+/* { dg-do compile { target { ! "mips*-*-* s390*-*-* avr-*-* mn10300-*-*" } }
} */
+/* { dg-options "-O2 -fdump-tree-gimple" } */
+/* { dg-options "-O2 -fdump-tree-gimple -march=i586" { target { i?86-*-* &&
ilp32 } } } */
+
+extern int doo1 (void);
+extern int doo2 (void);
+
+int bar (int a, int b, int c)
+{
+ if (a && b && c)
+ return doo1 ();
+ return doo2 ();
+}
+
+/* { dg-final { scan-tree-dump-times "if " 2 "gimple" } } */
+/* { dg-final { cleanup-tree-dump "gimple" } } */
Index: gcc-head/gcc/fold-const.c
===================================================================
--- gcc-head.orig/gcc/fold-const.c
+++ gcc-head/gcc/fold-const.c
@@ -8387,6 +8387,45 @@ fold_truth_andor (location_t loc, enum t
if ((tem = fold_truthop (loc, code, type, arg0, arg1)) != 0)
return tem;
+ if ((code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
+ && !TREE_SIDE_EFFECTS (arg1)
+ && LOGICAL_OP_NON_SHORT_CIRCUIT
+ /* floats might trap. */
+ && !FLOAT_TYPE_P (TREE_TYPE (arg1))
+ && ((TREE_CODE_CLASS (TREE_CODE (arg1)) != tcc_comparison
+ && TREE_CODE (arg1) != TRUTH_NOT_EXPR
+ && simple_operand_p (arg1))
+ || ((TREE_CODE_CLASS (TREE_CODE (arg1)) == tcc_comparison
+ || TREE_CODE (arg1) == TRUTH_NOT_EXPR)
+ /* Float comparison might trap. */
+ && !FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg1, 0)))
+ && simple_operand_p (TREE_OPERAND (arg1, 0)))))
+ {
+ /* We want to combine truth-comparison for
+ ((W TRUTH-ANDOR X) TRUTH-ANDORIF Y) TRUTH-ANDORIF Z,
+ if Y and Z are simple operands and have no side-effect to
+ ((W TRUTH-ANDOR X) TRUTH-IF (Y TRUTH-ANDOR Z). */
+ if (TREE_CODE (arg0) == code
+ && !TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1))
+ && simple_operand_p (TREE_OPERAND (arg0, 1)))
+ {
+ tem = build2_loc (loc,
+ (code == TRUTH_ANDIF_EXPR ? TRUTH_AND_EXPR
+ : TRUTH_OR_EXPR),
+ type, TREE_OPERAND (arg0, 1), arg1);
+ return build2_loc (loc, code, type, TREE_OPERAND (arg0, 0),
+ tem);
+ }
+ /* Convert X TRUTH-ANDORIF Y to X TRUTH-ANDOR Y, if X and Y
+ are simple operands and have no side-effects. */
+ if (simple_operand_p (arg0)
+ && !TREE_SIDE_EFFECTS (arg0))
+ return build2_loc (loc,
+ (code == TRUTH_ANDIF_EXPR ? TRUTH_AND_EXPR
+ : TRUTH_OR_EXPR),
+ type, arg0, arg1);
+ }
+
return NULL_TREE;
}
Index: gcc-head/gcc/testsuite/gcc.dg/tree-ssa/ssa-ifbranch-2.c
===================================================================
--- /dev/null
+++ gcc-head/gcc/testsuite/gcc.dg/tree-ssa/ssa-ifbranch-2.c
@@ -0,0 +1,18 @@
+/* Skip on MIPS, S/390, and AVR due LOGICAL_OP_NON_SHORT_CIRCUIT, and
+ lower values in BRANCH_COST. */
+/* { dg-do compile { target { ! "mips*-*-* s390*-*-* avr-*-* mn10300-*-*" } }
} */
+/* { dg-options "-O2 -fdump-tree-gimple" } */
+/* { dg-options "-O2 -fdump-tree-gimple -march=i586" { target { i?86-*-* &&
ilp32 } } } */
+
+extern int doo1 (void);
+extern int doo2 (void);
+
+int bar (int a, int b, int c, int d)
+{
+ if (a && b && c && d)
+ return doo1 ();
+ return doo2 ();
+}
+
+/* { dg-final { scan-tree-dump-times "if " 2 "gimple" } } */
+/* { dg-final { cleanup-tree-dump "gimple" } } */
Index: gcc-head/gcc/testsuite/gcc.dg/tree-ssa/ssa-ifbranch-3.c
===================================================================
--- /dev/null
+++ gcc-head/gcc/testsuite/gcc.dg/tree-ssa/ssa-ifbranch-3.c
@@ -0,0 +1,18 @@
+/* Skip on MIPS, S/390, and AVR due LOGICAL_OP_NON_SHORT_CIRCUIT, and
+ lower values in BRANCH_COST. */
+/* { dg-do compile { target { ! "mips*-*-* s390*-*-* avr-*-* mn10300-*-*" } }
} */
+/* { dg-options "-O2 -fdump-tree-gimple" } */
+/* { dg-options "-O2 -fdump-tree-gimple -march=i586" { target { i?86-*-* &&
ilp32 } } } */
+
+extern int doo1 (void);
+extern int doo2 (void);
+
+int bar (int a, int c)
+{
+ if (a && c)
+ return doo1 ();
+ return doo2 ();
+}
+
+/* { dg-final { scan-tree-dump-times "if " 1 "gimple" } } */
+/* { dg-final { cleanup-tree-dump "gimple" } } */
Index: gcc-head/gcc/testsuite/gcc.dg/tree-ssa/ssa-ifbranch-4.c
===================================================================
--- /dev/null
+++ gcc-head/gcc/testsuite/gcc.dg/tree-ssa/ssa-ifbranch-4.c
@@ -0,0 +1,18 @@
+/* Skip on MIPS, S/390, and AVR due LOGICAL_OP_NON_SHORT_CIRCUIT, and
+ lower values in BRANCH_COST. */
+/* { dg-do compile { target { ! "mips*-*-* s390*-*-* avr-*-* mn10300-*-*" } }
} */
+/* { dg-options "-O2 -fdump-tree-gimple" } */
+/* { dg-options "-O2 -fdump-tree-gimple -march=i586" { target { i?86-*-* &&
ilp32 } } } */
+
+extern int doo1 (void);
+extern int doo2 (void);
+
+int bar (int a, int b, int c, int d)
+{
+ if ((a && b) && (c && d))
+ return doo1 ();
+ return doo2 ();
+}
+
+/* { dg-final { scan-tree-dump-times "if " 2 "gimple" } } */
+/* { dg-final { cleanup-tree-dump "gimple" } } */
