ping ?
I have reorganised the last patch and now handling only
VIEW_CONVERT_EXPR, CONVERT_EXPR and NOP_EXPR. Once it is reviewed and
necessary changes are made, I will address the other cases as a separate
patch (when it reaches that stage).
Thanks,
Kugan
gcc/
+2014-01-07 Kugan Vivekanandarajah <kug...@linaro.org>
+
+ * dojump.c (do_compare_and_jump): Generate rtl without
+ zero/sign extension if redundant.
+ * cfgexpand.c (expand_gimple_stmt_1): Likewise.
+ (is_assigned_exp_fit_type) : New function.
+ * cfgexpand.h (is_assigned_exp_fit_type) : Declare.
+
diff --git a/gcc/cfgexpand.c b/gcc/cfgexpand.c
index 7a93975..b2e2f90 100644
--- a/gcc/cfgexpand.c
+++ b/gcc/cfgexpand.c
@@ -476,6 +476,66 @@ add_scope_conflicts_1 (basic_block bb, bitmap work, bool
for_conflict)
}
}
+
+/* Check gimple assign stmt and see if zero/sign extension is
+ redundant. i.e. if an assignment gimple statement has RHS expression
+ value that can fit in LHS type, subreg and extension to fit can be
+ redundant. Zero/sign extensions in this case can be removed. */
+
+bool
+is_assigned_exp_fit_type (tree lhs)
+{
+ double_int type_min, type_max;
+ double_int min1, max1;
+ enum tree_code stmt_code;
+ tree rhs1;
+ gimple stmt = SSA_NAME_DEF_STMT (lhs);
+
+ if (gimple_code (stmt) != GIMPLE_ASSIGN)
+ return false;
+
+ /* We remove extension for non-pointer and integral stmts. */
+ if (!INTEGRAL_TYPE_P (TREE_TYPE (lhs))
+ || POINTER_TYPE_P (TREE_TYPE (lhs)))
+ return false;
+
+ stmt_code = gimple_assign_rhs_code (stmt);
+ rhs1 = gimple_assign_rhs1 (stmt);
+ type_max = tree_to_double_int (TYPE_MAX_VALUE (TREE_TYPE (lhs)));
+ type_min = tree_to_double_int (TYPE_MIN_VALUE (TREE_TYPE (lhs)));
+
+ if (TREE_CODE_CLASS (stmt_code) == tcc_unary)
+ {
+ bool uns = TYPE_UNSIGNED (TREE_TYPE (rhs1));
+ /* Get the value range. */
+ if (TREE_CODE (rhs1) == INTEGER_CST)
+ {
+ min1 = tree_to_double_int (rhs1);
+ max1 = tree_to_double_int (rhs1);
+ }
+ else if (get_range_info (rhs1, &min1, &max1) != VR_RANGE)
+ return false;
+
+ switch (stmt_code)
+ {
+ case VIEW_CONVERT_EXPR:
+ case CONVERT_EXPR:
+ case NOP_EXPR:
+ /* If rhs value range fits lhs type, zero/sign extension is
+ redundant. */
+ if (max1.cmp (type_max, 0) != 1
+ && (type_min.cmp (min1, 0)) != 1)
+ return true;
+ else
+ return false;
+ default:
+ return false;
+ }
+ }
+
+ return false;
+}
+
/* Generate stack partition conflicts between all partitions that are
simultaneously live. */
@@ -3247,6 +3307,20 @@ expand_gimple_stmt_1 (gimple stmt)
if (temp == target)
;
+ /* If the value in SUBREG of temp fits that SUBREG (does not
+ overflow) and is assigned to target SUBREG of the same mode
+ without sign conversion, we can skip the SUBREG
+ and extension. */
+ else if (promoted
+ && is_assigned_exp_fit_type (lhs)
+ && (GET_CODE (temp) == SUBREG)
+ && (GET_MODE_PRECISION (GET_MODE (SUBREG_REG (temp)))
+ >= GET_MODE_PRECISION (GET_MODE (target)))
+ && (GET_MODE (SUBREG_REG (target))
+ == GET_MODE (SUBREG_REG (temp))))
+ {
+ emit_move_insn (SUBREG_REG (target), SUBREG_REG (temp));
+ }
else if (promoted)
{
int unsignedp = SUBREG_PROMOTED_UNSIGNED_P (target);
diff --git a/gcc/cfgexpand.h b/gcc/cfgexpand.h
index 04517a3..c7d73e8 100644
--- a/gcc/cfgexpand.h
+++ b/gcc/cfgexpand.h
@@ -22,5 +22,6 @@ along with GCC; see the file COPYING3. If not see
extern tree gimple_assign_rhs_to_tree (gimple);
extern HOST_WIDE_INT estimated_stack_frame_size (struct cgraph_node *);
+extern bool is_assigned_exp_fit_type (tree lhs);
#endif /* GCC_CFGEXPAND_H */
diff --git a/gcc/dojump.c b/gcc/dojump.c
index 73df6d1..73a4b6b 100644
--- a/gcc/dojump.c
+++ b/gcc/dojump.c
@@ -35,6 +35,7 @@ along with GCC; see the file COPYING3. If not see
#include "ggc.h"
#include "basic-block.h"
#include "tm_p.h"
+#include "cfgexpand.h"
static bool prefer_and_bit_test (enum machine_mode, int);
static void do_jump_by_parts_greater (tree, tree, int, rtx, rtx, int);
@@ -1166,6 +1167,62 @@ do_compare_and_jump (tree treeop0, tree treeop1, enum
rtx_code signed_code,
type = TREE_TYPE (treeop0);
mode = TYPE_MODE (type);
+
+ /* Is zero/sign extension redundant. */
+ bool op0_ext_redundant = false;
+ bool op1_ext_redundant = false;
+
+ /* If promoted and the value in SUBREG of op0 fits (does not overflow),
+ it is a candidate for extension elimination. */
+ if (GET_CODE (op0) == SUBREG && SUBREG_PROMOTED_VAR_P (op0))
+ op0_ext_redundant = is_assigned_exp_fit_type (treeop0);
+
+ /* If promoted and the value in SUBREG of op1 fits (does not overflow),
+ it is a candidate for extension elimination. */
+ if (GET_CODE (op1) == SUBREG && SUBREG_PROMOTED_VAR_P (op1))
+ op1_ext_redundant = is_assigned_exp_fit_type (treeop1);
+
+ /* If zero/sign extension is redundant, generate RTL
+ for operands without zero/sign extension. */
+ if ((op0_ext_redundant || TREE_CODE (treeop0) == INTEGER_CST)
+ && (op1_ext_redundant || TREE_CODE (treeop1) == INTEGER_CST))
+ {
+ if ((TREE_CODE (treeop1) == INTEGER_CST)
+ && (!mode_signbit_p (GET_MODE (op1), op1)))
+ {
+ /* First operand is constant and signbit is not set (not
+ represented in RTL as a negative constant). */
+ rtx new_op0 = gen_reg_rtx (GET_MODE (SUBREG_REG (op0)));
+ emit_move_insn (new_op0, SUBREG_REG (op0));
+ op0 = new_op0;
+ }
+ else if ((TREE_CODE (treeop0) == INTEGER_CST)
+ && (!mode_signbit_p (GET_MODE (op0), op0)))
+ {
+ /* Other operand is constant and signbit is not set (not
+ represented in RTL as a negative constant). */
+ rtx new_op1 = gen_reg_rtx (GET_MODE (SUBREG_REG (op1)));
+
+ emit_move_insn (new_op1, SUBREG_REG (op1));
+ op1 = new_op1;
+ }
+ else if ((TREE_CODE (treeop0) != INTEGER_CST)
+ && (TREE_CODE (treeop1) != INTEGER_CST)
+ && (GET_MODE (op0) == GET_MODE (op1))
+ && (GET_MODE (SUBREG_REG (op0)) == GET_MODE (SUBREG_REG (op1))))
+ {
+ /* If both comapre registers fits SUBREG and of the
+ same mode. */
+ rtx new_op0 = gen_reg_rtx (GET_MODE (SUBREG_REG (op0)));
+ rtx new_op1 = gen_reg_rtx (GET_MODE (SUBREG_REG (op1)));
+
+ emit_move_insn (new_op0, SUBREG_REG (op0));
+ emit_move_insn (new_op1, SUBREG_REG (op1));
+ op0 = new_op0;
+ op1 = new_op1;
+ }
+ }
+
if (TREE_CODE (treeop0) == INTEGER_CST
&& (TREE_CODE (treeop1) != INTEGER_CST
|| (GET_MODE_BITSIZE (mode)
