aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
Diffstat
-rw-r--r--gcc/ChangeLog8
-rw-r--r--gcc/expmed.c25
-rw-r--r--gcc/fold-const.c79
-rw-r--r--gcc/testsuite/ChangeLog4
-rw-r--r--gcc/testsuite/gcc.dg/20030804-1.c75
5 files changed, 175 insertions, 16 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 60a391c..daf0bec 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,13 @@
2003-08-04 Roger Sayle <roger@eyesopen.com>
+ * fold-const.c (fold <PLUS_EXPR>): Transform x+x into x*2.0.
+ Optimize x*c+x and x+x*c into x*(c+1) and x*c1+x*c2 into x*(c1+c2)
+ for floating point expressions with -ffast-math.
+ (fold <MULT_EXPR>): Don't transform x*2.0 into x+x.
+ * expmed.c (expand_mult): Wrap long line. Expand x*2.0 as x+x.
+
+2003-08-04 Roger Sayle <roger@eyesopen.com>
+
* c-common.c (flag_noniso_default_format_attributes): Delete.
(built_in_attribute): Don't define/undefine DEF_FN_ATTR.
(c_attrs_initialized): Delete.
diff --git a/gcc/expmed.c b/gcc/expmed.c
index 68163e9..89ecd0c 100644
--- a/gcc/expmed.c
+++ b/gcc/expmed.c
@@ -2300,7 +2300,8 @@ synth_mult (struct algorithm *alg_out, unsigned HOST_WIDE_INT t,
you should swap the two operands if OP0 would be constant. */
rtx
-expand_mult (enum machine_mode mode, rtx op0, rtx op1, rtx target, int unsignedp)
+expand_mult (enum machine_mode mode, rtx op0, rtx op1, rtx target,
+ int unsignedp)
{
rtx const_op1 = op1;
@@ -2514,6 +2515,28 @@ expand_mult (enum machine_mode mode, rtx op0, rtx op1, rtx target, int unsignedp
}
}
+ if (GET_CODE (op0) == CONST_DOUBLE)
+ {
+ rtx temp = op0;
+ op0 = op1;
+ op1 = temp;
+ }
+
+ /* Expand x*2.0 as x+x. */
+ if (GET_CODE (op1) == CONST_DOUBLE
+ && GET_MODE_CLASS (mode) == MODE_FLOAT)
+ {
+ REAL_VALUE_TYPE d;
+ REAL_VALUE_FROM_CONST_DOUBLE (d, op1);
+
+ if (REAL_VALUES_EQUAL (d, dconst2))
+ {
+ op0 = force_reg (GET_MODE (op0), op0);
+ return expand_binop (mode, add_optab, op0, op0,
+ target, unsignedp, OPTAB_LIB_WIDEN);
+ }
+ }
+
/* This used to use umul_optab if unsigned, but for non-widening multiply
there is no difference between signed and unsigned. */
op0 = expand_binop (mode,
diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index c4faf07..4dd606f 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -5659,14 +5659,72 @@ fold (tree expr)
same));
}
}
+ else
+ {
+ /* See if ARG1 is zero and X + ARG1 reduces to X. */
+ if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
+ return non_lvalue (convert (type, arg0));
- /* See if ARG1 is zero and X + ARG1 reduces to X. */
- else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
- return non_lvalue (convert (type, arg0));
+ /* Likewise if the operands are reversed. */
+ if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
+ return non_lvalue (convert (type, arg1));
- /* Likewise if the operands are reversed. */
- else if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
- return non_lvalue (convert (type, arg1));
+ /* Convert x+x into x*2.0. */
+ if (operand_equal_p (arg0, arg1, 0))
+ return fold (build (MULT_EXPR, type, arg0,
+ build_real (type, dconst2)));
+
+ /* Convert x*c+x into x*(c+1). */
+ if (flag_unsafe_math_optimizations
+ && TREE_CODE (arg0) == MULT_EXPR
+ && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
+ && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
+ && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
+ {
+ REAL_VALUE_TYPE c;
+
+ c = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
+ real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
+ return fold (build (MULT_EXPR, type, arg1,
+ build_real (type, c)));
+ }
+
+ /* Convert x+x*c into x*(c+1). */
+ if (flag_unsafe_math_optimizations
+ && TREE_CODE (arg1) == MULT_EXPR
+ && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
+ && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
+ && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
+ {
+ REAL_VALUE_TYPE c;
+
+ c = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
+ real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
+ return fold (build (MULT_EXPR, type, arg0,
+ build_real (type, c)));
+ }
+
+ /* Convert x*c1+x*c2 into x*(c1+c2). */
+ if (flag_unsafe_math_optimizations
+ && TREE_CODE (arg0) == MULT_EXPR
+ && TREE_CODE (arg1) == MULT_EXPR
+ && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
+ && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
+ && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
+ && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
+ && operand_equal_p (TREE_OPERAND (arg0, 0),
+ TREE_OPERAND (arg1, 0), 0))
+ {
+ REAL_VALUE_TYPE c1, c2;
+
+ c1 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
+ c2 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
+ real_arithmetic (&c1, PLUS_EXPR, &c1, &c2);
+ return fold (build (MULT_EXPR, type,
+ TREE_OPERAND (arg0, 0),
+ build_real (type, c1)));
+ }
+ }
bit_rotate:
/* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
@@ -5954,15 +6012,6 @@ fold (tree expr)
&& real_minus_onep (arg1))
return fold (build1 (NEGATE_EXPR, type, arg0));
- /* x*2 is x+x */
- if (! wins && real_twop (arg1)
- && (*lang_hooks.decls.global_bindings_p) () == 0
- && ! CONTAINS_PLACEHOLDER_P (arg0))
- {
- tree arg = save_expr (arg0);
- return fold (build (PLUS_EXPR, type, arg, arg));
- }
-
if (flag_unsafe_math_optimizations)
{
enum built_in_function fcode0 = builtin_mathfn_code (arg0);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 862280a..ba19bc8 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2003-08-04 Roger Sayle <roger@eyesopen.com>
+
+ * gcc.dg/20030804-1.c: New test case.
+
2003-08-04 Alexandre Oliva <aoliva@redhat.com>
* gcc.dg/cpp/separate-1.c: New test.
diff --git a/gcc/testsuite/gcc.dg/20030804-1.c b/gcc/testsuite/gcc.dg/20030804-1.c
new file mode 100644
index 0000000..cbc6647
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/20030804-1.c
@@ -0,0 +1,75 @@
+/* Copyright (C) 2003 Free Software Foundation.
+
+ Check that constant folding of mathematical expressions doesn't
+ break anything.
+
+ Written by Roger Sayle, 3rd August 2003. */
+
+/* { dg-do link } */
+/* { dg-options "-O2 -ffast-math" } */
+
+extern void link_error(void);
+
+void test(double x)
+{
+ if (x+x != 2.0*x)
+ link_error ();
+ if (x+x != x*2.0)
+ link_error ();
+
+ if (x+x+x != 3.0*x)
+ link_error ();
+ if (x+x+x != x*3.0)
+ link_error ();
+
+ if ((x+x)+x != 3.0*x)
+ link_error ();
+ if ((x+x)+x != x*3.0)
+ link_error ();
+
+ if (x+(x+x) != 3.0*x)
+ link_error ();
+ if (x+(x+x) != x*3.0)
+ link_error ();
+
+ if (x+4.0*x != 5.0*x)
+ link_error ();
+ if (x+4.0*x != x*5.0)
+ link_error ();
+ if (x+x*4.0 != 5.0*x)
+ link_error ();
+ if (x+x*4.0 != x*5.0)
+ link_error ();
+ if (4.0*x+x != 5.0*x)
+ link_error ();
+ if (4.0*x+x != x*5.0)
+ link_error ();
+ if (x*4.0+x != 5.0*x)
+ link_error ();
+ if (x*4.0+x != x*5.0)
+ link_error ();
+
+ if (3.0*x + 5.0*x != 8.0*x)
+ link_error ();
+ if (3.0*x + 5.0*x != x*8.0)
+ link_error ();
+ if (x*3.0 + 5.0*x != 8.0*x)
+ link_error ();
+ if (x*3.0 + 5.0*x != x*8.0)
+ link_error ();
+ if (3.0*x + x*5.0 != 8.0*x)
+ link_error ();
+ if (3.0*x + x*5.0 != x*8.0)
+ link_error ();
+ if (x*3.0 + x*5.0 != 8.0*x)
+ link_error ();
+ if (x*3.0 + x*5.0 != x*8.0)
+ link_error ();
+}
+
+int main()
+{
+ test(2.0);
+ return 0;
+}
+
generated by cgit v1.1 at 2025-02-22 07:32:54 +0000