This handles $subject which allows us to simplify the return expression
all the way to w for the following testcase (going via
pow (x, -0.5) * x -> pow (x, 0.5) -> sqrt (w * w) -> w)
double test4 (double w)
{
double x = w * w;
double y = __builtin_pow (x, -0.5);
return y * x;
}
Committed to the branch.
Richard.
2014-05-14 Richard Biener <rguent...@suse.de>
* gimple-match-head.c (REAL_CST_P): New predicate.
(gimple_match_and_simplify): Support re-simplification of
two-argument builtin functions.
* match.pd: Add pattern simplifying pow (x, 0.5) to sqrt (x).
testsuite/
* gcc.dg/tree-ssa/match-1.c: Add testcase involving two-argument
function re-simplification.
Index: gcc/gimple-match-head.c
===================================================================
--- gcc/gimple-match-head.c (revision 210415)
+++ gcc/gimple-match-head.c (working copy)
@@ -38,6 +38,7 @@ along with GCC; see the file COPYING3.
#define INTEGER_CST_P(node) (TREE_CODE(node) == INTEGER_CST)
#define integral_op_p(node) INTEGRAL_TYPE_P(TREE_TYPE(node))
+#define REAL_CST_P(node) (TREE_CODE(node) == REAL_CST)
/* Helper to transparently allow tree codes and builtin function codes
@@ -495,6 +496,27 @@ gimple_match_and_simplify (gimple stmt,
rcode, ops,
seq, valueize);
}
+ case 2:
+ {
+ tree arg1 = gimple_call_arg (stmt, 0);
+ if (valueize && TREE_CODE (arg1) == SSA_NAME)
+ {
+ arg1 = valueize (arg1);
+ if (!arg1)
+ return false;
+ }
+ tree arg2 = gimple_call_arg (stmt, 0);
+ if (valueize && TREE_CODE (arg2) == SSA_NAME)
+ {
+ arg2 = valueize (arg2);
+ if (!arg2)
+ return false;
+ }
+ return gimple_match_and_simplify (DECL_FUNCTION_CODE (decl),
+ type, arg1, arg2,
+ rcode, ops,
+ seq, valueize);
+ }
default:
return false;
}
Index: gcc/match.pd
===================================================================
--- gcc/match.pd (revision 210414)
+++ gcc/match.pd (working copy)
@@ -163,6 +163,10 @@ to (minus @1 @0)
(match_and_simplify
(mult (BUILT_IN_POW @0 @1) @0)
(BUILT_IN_POW @0 (PLUS_EXPR @1 { build_one_cst (TREE_TYPE (@1)); })))
+(match_and_simplify
+ (BUILT_IN_POW @0 REAL_CST_P@1)
+ if (REAL_VALUES_EQUAL (TREE_REAL_CST (@1), dconsthalf))
+ (BUILT_IN_SQRT @0))
/* ????s
Index: gcc/testsuite/gcc.dg/tree-ssa/match-1.c
===================================================================
--- gcc/testsuite/gcc.dg/tree-ssa/match-1.c (revision 210414)
+++ gcc/testsuite/gcc.dg/tree-ssa/match-1.c (working copy)
@@ -1,5 +1,5 @@
/* { dg-do compile } */
-/* { dg-options "-O -fdump-tree-forwprop" } */
+/* { dg-options "-O -fdump-tree-forwprop1-details" } */
double test1 (_Complex double z)
{
@@ -7,6 +7,8 @@ double test1 (_Complex double z)
return __builtin_cabs (z);
}
+/* { dg-final { scan-tree-dump "gimple_match_and_simplified to \[^\n\r\]*fabs"
"forwprop1" } } */
+
double test2 (double x)
{
_Complex z = x;
@@ -14,12 +16,23 @@ double test2 (double x)
return __builtin_cabs (z);
}
+/* { dg-final { scan-tree-dump "gimple_match_and_simplified to \[^\n\r\]*=
_\\d\+ \\* 1.41" "forwprop1" } } */
+
double test3 (double x)
{
double y = __builtin_pow (x, 5.);
return y * x;
}
-/* { dg-final { scan-tree-dump-not "cabs" "forwprop1" } } */
-/* { dg-final { scan-tree-dump "pow \\\(\[^,\]*, 6" "forwprop1" } } */
-/* { dg-final { cleanup-tree-dump "forwprop2" } } */
+/* { dg-final { scan-tree-dump "gimple_match_and_simplified to \[^\n\r\]*pow
\\(x_\\d\+\\(D\\), 6" "forwprop1" } } */
+
+double test4 (double w)
+{
+ double x = w * w;
+ double y = __builtin_pow (x, -0.5);
+ return y * x;
+}
+
+/* { dg-final { scan-tree-dump "gimple_match_and_simplified to \[^\n\r\]*=
w_\\d\+\\(D\\)" "forwprop1" } } */
+
+/* { dg-final { cleanup-tree-dump "forwprop1" } } */
