This update changes only the context modified by changes to patch 2. The
patch has already been approved. I'm just posting it for completeness.
Andrew
2011-07-14 Andrew Stubbs <a...@codesourcery.com>
gcc/
* tree-ssa-math-opts.c (convert_plusminus_to_widen): Permit a single
conversion statement separating multiply-and-accumulate.
gcc/testsuite/
* gcc.target/arm/wmul-5.c: New file.
* gcc.target/arm/no-wmla-1.c: New file.
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/no-wmla-1.c
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -march=armv7-a" } */
+
+int
+foo (int a, short b, short c)
+{
+ int bc = b * c;
+ return a + (short)bc;
+}
+
+/* { dg-final { scan-assembler "mul" } } */
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/wmul-5.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -march=armv7-a" } */
+
+long long
+foo (long long a, char *b, char *c)
+{
+ return a + *b * *c;
+}
+
+/* { dg-final { scan-assembler "umlal" } } */
--- a/gcc/tree-ssa-math-opts.c
+++ b/gcc/tree-ssa-math-opts.c
@@ -2135,6 +2135,7 @@ convert_plusminus_to_widen (gimple_stmt_iterator *gsi, gimple stmt,
enum tree_code code)
{
gimple rhs1_stmt = NULL, rhs2_stmt = NULL;
+ gimple conv1_stmt = NULL, conv2_stmt = NULL, conv_stmt;
tree type, type1, type2, tmp;
tree lhs, rhs1, rhs2, mult_rhs1, mult_rhs2, add_rhs;
enum tree_code rhs1_code = ERROR_MARK, rhs2_code = ERROR_MARK;
@@ -2177,6 +2178,38 @@ convert_plusminus_to_widen (gimple_stmt_iterator *gsi, gimple stmt,
else
return false;
+ /* Allow for one conversion statement between the multiply
+ and addition/subtraction statement. If there are more than
+ one conversions then we assume they would invalidate this
+ transformation. If that's not the case then they should have
+ been folded before now. */
+ if (CONVERT_EXPR_CODE_P (rhs1_code))
+ {
+ conv1_stmt = rhs1_stmt;
+ rhs1 = gimple_assign_rhs1 (rhs1_stmt);
+ if (TREE_CODE (rhs1) == SSA_NAME)
+ {
+ rhs1_stmt = SSA_NAME_DEF_STMT (rhs1);
+ if (is_gimple_assign (rhs1_stmt))
+ rhs1_code = gimple_assign_rhs_code (rhs1_stmt);
+ }
+ else
+ return false;
+ }
+ if (CONVERT_EXPR_CODE_P (rhs2_code))
+ {
+ conv2_stmt = rhs2_stmt;
+ rhs2 = gimple_assign_rhs1 (rhs2_stmt);
+ if (TREE_CODE (rhs2) == SSA_NAME)
+ {
+ rhs2_stmt = SSA_NAME_DEF_STMT (rhs2);
+ if (is_gimple_assign (rhs2_stmt))
+ rhs2_code = gimple_assign_rhs_code (rhs2_stmt);
+ }
+ else
+ return false;
+ }
+
/* If code is WIDEN_MULT_EXPR then it would seem unnecessary to call
is_widening_mult_p, but we still need the rhs returns.
@@ -2190,6 +2223,7 @@ convert_plusminus_to_widen (gimple_stmt_iterator *gsi, gimple stmt,
&type2, &mult_rhs2))
return false;
add_rhs = rhs2;
+ conv_stmt = conv1_stmt;
}
else if (rhs2_code == MULT_EXPR || rhs2_code == WIDEN_MULT_EXPR)
{
@@ -2197,6 +2231,7 @@ convert_plusminus_to_widen (gimple_stmt_iterator *gsi, gimple stmt,
&type2, &mult_rhs2))
return false;
add_rhs = rhs1;
+ conv_stmt = conv2_stmt;
}
else
return false;
@@ -2207,6 +2242,33 @@ convert_plusminus_to_widen (gimple_stmt_iterator *gsi, gimple stmt,
if (TYPE_UNSIGNED (type1) != TYPE_UNSIGNED (type2))
return false;
+ /* If there was a conversion between the multiply and addition
+ then we need to make sure it fits a multiply-and-accumulate.
+ The should be a single mode change which does not change the
+ value. */
+ if (conv_stmt)
+ {
+ tree from_type = TREE_TYPE (gimple_assign_rhs1 (conv_stmt));
+ tree to_type = TREE_TYPE (gimple_assign_lhs (conv_stmt));
+ int data_size = TYPE_PRECISION (type1) + TYPE_PRECISION (type2);
+ bool is_unsigned = TYPE_UNSIGNED (type1) && TYPE_UNSIGNED (type2);
+
+ if (TYPE_PRECISION (from_type) > TYPE_PRECISION (to_type))
+ {
+ /* Conversion is a truncate. */
+ if (TYPE_PRECISION (to_type) < data_size)
+ return false;
+ }
+ else if (TYPE_PRECISION (from_type) < TYPE_PRECISION (to_type))
+ {
+ /* Conversion is an extend. Check it's the right sort. */
+ if (TYPE_UNSIGNED (from_type) != is_unsigned
+ && !(is_unsigned && TYPE_PRECISION (from_type) > data_size))
+ return false;
+ }
+ /* else convert is a no-op for our purposes. */
+ }
+
/* Verify that the machine can perform a widening multiply
accumulate in this mode/signedness combination, otherwise
this transformation is likely to pessimize code. */
