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-rw-r--r--gcc/ChangeLog8
-rw-r--r--gcc/simplify-rtx.c90
-rw-r--r--gcc/testsuite/ChangeLog5
-rw-r--r--gcc/testsuite/gcc.target/i386/badshift.c28
4 files changed, 113 insertions, 18 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 081b91a62d7..933e4e446eb 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2005-03-24 Alexandre Oliva <aoliva@redhat.com>
+
+ PR rtl-optimization/20532
+ * simplify-rtx.c (simplify_binary_operation_1): Protect from
+ overflow when adding coefficients for PLUS or MINUS.
+ (simplify_binary_operation_1): Handle CONST_DOUBLE exact power of
+ two as multiplier.
+
2005-03-23 Joseph S. Myers <joseph@codesourcery.com>
* langhooks.h (truthvalue_conversion): Remove.
diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c
index a7033315e98..865d6f933bb 100644
--- a/gcc/simplify-rtx.c
+++ b/gcc/simplify-rtx.c
@@ -1257,44 +1257,67 @@ simplify_binary_operation_1 (enum rtx_code code, enum machine_mode mode,
if (! FLOAT_MODE_P (mode))
{
- HOST_WIDE_INT coeff0 = 1, coeff1 = 1;
+ HOST_WIDE_INT coeff0h = 0, coeff1h = 0;
+ unsigned HOST_WIDE_INT coeff0l = 1, coeff1l = 1;
rtx lhs = op0, rhs = op1;
if (GET_CODE (lhs) == NEG)
- coeff0 = -1, lhs = XEXP (lhs, 0);
+ {
+ coeff0l = -1;
+ coeff0h = -1;
+ lhs = XEXP (lhs, 0);
+ }
else if (GET_CODE (lhs) == MULT
&& GET_CODE (XEXP (lhs, 1)) == CONST_INT)
- coeff0 = INTVAL (XEXP (lhs, 1)), lhs = XEXP (lhs, 0);
+ {
+ coeff0l = INTVAL (XEXP (lhs, 1));
+ coeff0h = INTVAL (XEXP (lhs, 1)) < 0 ? -1 : 0;
+ lhs = XEXP (lhs, 0);
+ }
else if (GET_CODE (lhs) == ASHIFT
&& GET_CODE (XEXP (lhs, 1)) == CONST_INT
&& INTVAL (XEXP (lhs, 1)) >= 0
&& INTVAL (XEXP (lhs, 1)) < HOST_BITS_PER_WIDE_INT)
{
- coeff0 = ((HOST_WIDE_INT) 1) << INTVAL (XEXP (lhs, 1));
+ coeff0l = ((HOST_WIDE_INT) 1) << INTVAL (XEXP (lhs, 1));
+ coeff0h = 0;
lhs = XEXP (lhs, 0);
}
if (GET_CODE (rhs) == NEG)
- coeff1 = -1, rhs = XEXP (rhs, 0);
+ {
+ coeff1l = -1;
+ coeff1h = -1;
+ rhs = XEXP (rhs, 0);
+ }
else if (GET_CODE (rhs) == MULT
&& GET_CODE (XEXP (rhs, 1)) == CONST_INT)
{
- coeff1 = INTVAL (XEXP (rhs, 1)), rhs = XEXP (rhs, 0);
+ coeff1l = INTVAL (XEXP (rhs, 1));
+ coeff1h = INTVAL (XEXP (rhs, 1)) < 0 ? -1 : 0;
+ rhs = XEXP (rhs, 0);
}
else if (GET_CODE (rhs) == ASHIFT
&& GET_CODE (XEXP (rhs, 1)) == CONST_INT
&& INTVAL (XEXP (rhs, 1)) >= 0
&& INTVAL (XEXP (rhs, 1)) < HOST_BITS_PER_WIDE_INT)
{
- coeff1 = ((HOST_WIDE_INT) 1) << INTVAL (XEXP (rhs, 1));
+ coeff1l = ((HOST_WIDE_INT) 1) << INTVAL (XEXP (rhs, 1));
+ coeff1h = 0;
rhs = XEXP (rhs, 0);
}
if (rtx_equal_p (lhs, rhs))
{
rtx orig = gen_rtx_PLUS (mode, op0, op1);
- tem = simplify_gen_binary (MULT, mode, lhs,
- GEN_INT (coeff0 + coeff1));
+ rtx coeff;
+ unsigned HOST_WIDE_INT l;
+ HOST_WIDE_INT h;
+
+ add_double (coeff0l, coeff0h, coeff1l, coeff1h, &l, &h);
+ coeff = immed_double_const (l, h, mode);
+
+ tem = simplify_gen_binary (MULT, mode, lhs, coeff);
return rtx_cost (tem, SET) <= rtx_cost (orig, SET)
? tem : 0;
}
@@ -1405,46 +1428,67 @@ simplify_binary_operation_1 (enum rtx_code code, enum machine_mode mode,
if (! FLOAT_MODE_P (mode))
{
- HOST_WIDE_INT coeff0 = 1, coeff1 = 1;
+ HOST_WIDE_INT coeff0h = 0, negcoeff1h = -1;
+ unsigned HOST_WIDE_INT coeff0l = 1, negcoeff1l = -1;
rtx lhs = op0, rhs = op1;
if (GET_CODE (lhs) == NEG)
- coeff0 = -1, lhs = XEXP (lhs, 0);
+ {
+ coeff0l = -1;
+ coeff0h = -1;
+ lhs = XEXP (lhs, 0);
+ }
else if (GET_CODE (lhs) == MULT
&& GET_CODE (XEXP (lhs, 1)) == CONST_INT)
{
- coeff0 = INTVAL (XEXP (lhs, 1)), lhs = XEXP (lhs, 0);
+ coeff0l = INTVAL (XEXP (lhs, 1));
+ coeff0h = INTVAL (XEXP (lhs, 1)) < 0 ? -1 : 0;
+ lhs = XEXP (lhs, 0);
}
else if (GET_CODE (lhs) == ASHIFT
&& GET_CODE (XEXP (lhs, 1)) == CONST_INT
&& INTVAL (XEXP (lhs, 1)) >= 0
&& INTVAL (XEXP (lhs, 1)) < HOST_BITS_PER_WIDE_INT)
{
- coeff0 = ((HOST_WIDE_INT) 1) << INTVAL (XEXP (lhs, 1));
+ coeff0l = ((HOST_WIDE_INT) 1) << INTVAL (XEXP (lhs, 1));
+ coeff0h = 0;
lhs = XEXP (lhs, 0);
}
if (GET_CODE (rhs) == NEG)
- coeff1 = - 1, rhs = XEXP (rhs, 0);
+ {
+ negcoeff1l = 1;
+ negcoeff1h = 0;
+ rhs = XEXP (rhs, 0);
+ }
else if (GET_CODE (rhs) == MULT
&& GET_CODE (XEXP (rhs, 1)) == CONST_INT)
{
- coeff1 = INTVAL (XEXP (rhs, 1)), rhs = XEXP (rhs, 0);
+ negcoeff1l = -INTVAL (XEXP (rhs, 1));
+ negcoeff1h = INTVAL (XEXP (rhs, 1)) <= 0 ? 0 : -1;
+ rhs = XEXP (rhs, 0);
}
else if (GET_CODE (rhs) == ASHIFT
&& GET_CODE (XEXP (rhs, 1)) == CONST_INT
&& INTVAL (XEXP (rhs, 1)) >= 0
&& INTVAL (XEXP (rhs, 1)) < HOST_BITS_PER_WIDE_INT)
{
- coeff1 = ((HOST_WIDE_INT) 1) << INTVAL (XEXP (rhs, 1));
+ negcoeff1l = -(((HOST_WIDE_INT) 1) << INTVAL (XEXP (rhs, 1)));
+ negcoeff1h = -1;
rhs = XEXP (rhs, 0);
}
if (rtx_equal_p (lhs, rhs))
{
rtx orig = gen_rtx_MINUS (mode, op0, op1);
- tem = simplify_gen_binary (MULT, mode, lhs,
- GEN_INT (coeff0 - coeff1));
+ rtx coeff;
+ unsigned HOST_WIDE_INT l;
+ HOST_WIDE_INT h;
+
+ add_double (coeff0l, coeff0h, negcoeff1l, negcoeff1h, &l, &h);
+ coeff = immed_double_const (l, h, mode);
+
+ tem = simplify_gen_binary (MULT, mode, lhs, coeff);
return rtx_cost (tem, SET) <= rtx_cost (orig, SET)
? tem : 0;
}
@@ -1531,6 +1575,16 @@ simplify_binary_operation_1 (enum rtx_code code, enum machine_mode mode,
|| val != HOST_BITS_PER_WIDE_INT - 1))
return simplify_gen_binary (ASHIFT, mode, op0, GEN_INT (val));
+ /* Likewise for multipliers wider than a word. */
+ else if (GET_CODE (trueop1) == CONST_DOUBLE
+ && (GET_MODE (trueop1) == VOIDmode
+ || GET_MODE_CLASS (GET_MODE (trueop1)) == MODE_INT)
+ && GET_MODE (op0) == mode
+ && CONST_DOUBLE_LOW (trueop1) == 0
+ && (val = exact_log2 (CONST_DOUBLE_HIGH (trueop1))) >= 0)
+ return simplify_gen_binary (ASHIFT, mode, op0,
+ GEN_INT (val + HOST_BITS_PER_WIDE_INT));
+
/* x*2 is x+x and x*(-1) is -x */
if (GET_CODE (trueop1) == CONST_DOUBLE
&& GET_MODE_CLASS (GET_MODE (trueop1)) == MODE_FLOAT
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 465d516f451..41fd479b52d 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2005-03-24 Alexandre Oliva <aoliva@redhat.com>
+
+ PR rtl-optimization/20532
+ * gcc.target/i386/badshift.c: New.
+
2005-03-23 Francois-Xavier Coudert <coudert@clipper.ens.fr>
* pr18025.f90: New test.
diff --git a/gcc/testsuite/gcc.target/i386/badshift.c b/gcc/testsuite/gcc.target/i386/badshift.c
new file mode 100644
index 00000000000..ddbf6130b8e
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/badshift.c
@@ -0,0 +1,28 @@
+/* PR rtl-optimization/20532 */
+
+/* { dg-do run } */
+/* { dg-options "-m32 -march=i386 -O1" } */
+
+/* We used to optimize the DImode shift-by-32 to zero because in combine
+ we turned:
+
+ (v << 31) * (v << 31)
+
+ into:
+
+ (v * (((HOST_WIDE_INT)1 << 31) + ((HOST_WIDE_INT)1 << 31)))
+
+ With a 32-bit HOST_WIDE_INT, the coefficient overflowed to zero. */
+
+unsigned long long int badshift(unsigned long long int v)
+{
+ return v << 31 << 1;
+}
+
+extern void abort ();
+
+int main() {
+ if (badshift (1) == 0)
+ abort ();
+ return 0;
+}
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