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* [gcc r14-1009] Move fold_single_bit_test to expr.cc from fold-const.cc
@ 2023-05-20 5:05 Andrew Pinski
0 siblings, 0 replies; only message in thread
From: Andrew Pinski @ 2023-05-20 5:05 UTC (permalink / raw)
To: gcc-cvs
https://gcc.gnu.org/g:7bde4c3dcdecac82e080731fc8bb362e6c024628
commit r14-1009-g7bde4c3dcdecac82e080731fc8bb362e6c024628
Author: Andrew Pinski <apinski@marvell.com>
Date: Fri May 19 16:20:23 2023 +0000
Move fold_single_bit_test to expr.cc from fold-const.cc
This is part 1 of N patch set that will change the expansion
of `(A & C) != 0` from using trees to directly expanding so later
on we can do some cost analysis.
Since the only user of fold_single_bit_test is now
expand, move it to there.
gcc/ChangeLog:
* fold-const.cc (fold_single_bit_test_into_sign_test): Move to
expr.cc.
(fold_single_bit_test): Likewise.
* expr.cc (fold_single_bit_test_into_sign_test): Move from fold-const.cc
(fold_single_bit_test): Likewise and make static.
* fold-const.h (fold_single_bit_test): Remove declaration.
Diff:
---
gcc/expr.cc | 113 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
gcc/fold-const.cc | 112 -----------------------------------------------------
gcc/fold-const.h | 1 -
3 files changed, 113 insertions(+), 113 deletions(-)
diff --git a/gcc/expr.cc b/gcc/expr.cc
index 5ede094e705..f999f81af4a 100644
--- a/gcc/expr.cc
+++ b/gcc/expr.cc
@@ -12898,6 +12898,119 @@ maybe_optimize_sub_cmp_0 (enum tree_code code, tree *arg0, tree *arg1)
*arg1 = treeop1;
}
\f
+
+
+/* If CODE with arguments ARG0 and ARG1 represents a single bit
+ equality/inequality test, then return a simplified form of the test
+ using a sign testing. Otherwise return NULL. TYPE is the desired
+ result type. */
+
+static tree
+fold_single_bit_test_into_sign_test (location_t loc,
+ enum tree_code code, tree arg0, tree arg1,
+ tree result_type)
+{
+ /* If this is testing a single bit, we can optimize the test. */
+ if ((code == NE_EXPR || code == EQ_EXPR)
+ && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
+ && integer_pow2p (TREE_OPERAND (arg0, 1)))
+ {
+ /* If we have (A & C) != 0 where C is the sign bit of A, convert
+ this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
+ tree arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
+
+ if (arg00 != NULL_TREE
+ /* This is only a win if casting to a signed type is cheap,
+ i.e. when arg00's type is not a partial mode. */
+ && type_has_mode_precision_p (TREE_TYPE (arg00)))
+ {
+ tree stype = signed_type_for (TREE_TYPE (arg00));
+ return fold_build2_loc (loc, code == EQ_EXPR ? GE_EXPR : LT_EXPR,
+ result_type,
+ fold_convert_loc (loc, stype, arg00),
+ build_int_cst (stype, 0));
+ }
+ }
+
+ return NULL_TREE;
+}
+
+/* If CODE with arguments ARG0 and ARG1 represents a single bit
+ equality/inequality test, then return a simplified form of
+ the test using shifts and logical operations. Otherwise return
+ NULL. TYPE is the desired result type. */
+
+static tree
+fold_single_bit_test (location_t loc, enum tree_code code,
+ tree arg0, tree arg1, tree result_type)
+{
+ /* If this is testing a single bit, we can optimize the test. */
+ if ((code == NE_EXPR || code == EQ_EXPR)
+ && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
+ && integer_pow2p (TREE_OPERAND (arg0, 1)))
+ {
+ tree inner = TREE_OPERAND (arg0, 0);
+ tree type = TREE_TYPE (arg0);
+ int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
+ scalar_int_mode operand_mode = SCALAR_INT_TYPE_MODE (type);
+ int ops_unsigned;
+ tree signed_type, unsigned_type, intermediate_type;
+ tree tem, one;
+
+ /* First, see if we can fold the single bit test into a sign-bit
+ test. */
+ tem = fold_single_bit_test_into_sign_test (loc, code, arg0, arg1,
+ result_type);
+ if (tem)
+ return tem;
+
+ /* Otherwise we have (A & C) != 0 where C is a single bit,
+ convert that into ((A >> C2) & 1). Where C2 = log2(C).
+ Similarly for (A & C) == 0. */
+
+ /* If INNER is a right shift of a constant and it plus BITNUM does
+ not overflow, adjust BITNUM and INNER. */
+ if (TREE_CODE (inner) == RSHIFT_EXPR
+ && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
+ && bitnum < TYPE_PRECISION (type)
+ && wi::ltu_p (wi::to_wide (TREE_OPERAND (inner, 1)),
+ TYPE_PRECISION (type) - bitnum))
+ {
+ bitnum += tree_to_uhwi (TREE_OPERAND (inner, 1));
+ inner = TREE_OPERAND (inner, 0);
+ }
+
+ /* If we are going to be able to omit the AND below, we must do our
+ operations as unsigned. If we must use the AND, we have a choice.
+ Normally unsigned is faster, but for some machines signed is. */
+ ops_unsigned = (load_extend_op (operand_mode) == SIGN_EXTEND
+ && !flag_syntax_only) ? 0 : 1;
+
+ signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
+ unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
+ intermediate_type = ops_unsigned ? unsigned_type : signed_type;
+ inner = fold_convert_loc (loc, intermediate_type, inner);
+
+ if (bitnum != 0)
+ inner = build2 (RSHIFT_EXPR, intermediate_type,
+ inner, size_int (bitnum));
+
+ one = build_int_cst (intermediate_type, 1);
+
+ if (code == EQ_EXPR)
+ inner = fold_build2_loc (loc, BIT_XOR_EXPR, intermediate_type, inner, one);
+
+ /* Put the AND last so it can combine with more things. */
+ inner = build2 (BIT_AND_EXPR, intermediate_type, inner, one);
+
+ /* Make sure to return the proper type. */
+ inner = fold_convert_loc (loc, result_type, inner);
+
+ return inner;
+ }
+ return NULL_TREE;
+}
+
/* Generate code to calculate OPS, and exploded expression
using a store-flag instruction and return an rtx for the result.
OPS reflects a comparison.
diff --git a/gcc/fold-const.cc b/gcc/fold-const.cc
index a73b972ab9a..25466e97220 100644
--- a/gcc/fold-const.cc
+++ b/gcc/fold-const.cc
@@ -7433,118 +7433,6 @@ fold_div_compare (enum tree_code code, tree c1, tree c2, tree *lo,
return code;
}
-
-/* If CODE with arguments ARG0 and ARG1 represents a single bit
- equality/inequality test, then return a simplified form of the test
- using a sign testing. Otherwise return NULL. TYPE is the desired
- result type. */
-
-static tree
-fold_single_bit_test_into_sign_test (location_t loc,
- enum tree_code code, tree arg0, tree arg1,
- tree result_type)
-{
- /* If this is testing a single bit, we can optimize the test. */
- if ((code == NE_EXPR || code == EQ_EXPR)
- && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
- && integer_pow2p (TREE_OPERAND (arg0, 1)))
- {
- /* If we have (A & C) != 0 where C is the sign bit of A, convert
- this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
- tree arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
-
- if (arg00 != NULL_TREE
- /* This is only a win if casting to a signed type is cheap,
- i.e. when arg00's type is not a partial mode. */
- && type_has_mode_precision_p (TREE_TYPE (arg00)))
- {
- tree stype = signed_type_for (TREE_TYPE (arg00));
- return fold_build2_loc (loc, code == EQ_EXPR ? GE_EXPR : LT_EXPR,
- result_type,
- fold_convert_loc (loc, stype, arg00),
- build_int_cst (stype, 0));
- }
- }
-
- return NULL_TREE;
-}
-
-/* If CODE with arguments ARG0 and ARG1 represents a single bit
- equality/inequality test, then return a simplified form of
- the test using shifts and logical operations. Otherwise return
- NULL. TYPE is the desired result type. */
-
-tree
-fold_single_bit_test (location_t loc, enum tree_code code,
- tree arg0, tree arg1, tree result_type)
-{
- /* If this is testing a single bit, we can optimize the test. */
- if ((code == NE_EXPR || code == EQ_EXPR)
- && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
- && integer_pow2p (TREE_OPERAND (arg0, 1)))
- {
- tree inner = TREE_OPERAND (arg0, 0);
- tree type = TREE_TYPE (arg0);
- int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
- scalar_int_mode operand_mode = SCALAR_INT_TYPE_MODE (type);
- int ops_unsigned;
- tree signed_type, unsigned_type, intermediate_type;
- tree tem, one;
-
- /* First, see if we can fold the single bit test into a sign-bit
- test. */
- tem = fold_single_bit_test_into_sign_test (loc, code, arg0, arg1,
- result_type);
- if (tem)
- return tem;
-
- /* Otherwise we have (A & C) != 0 where C is a single bit,
- convert that into ((A >> C2) & 1). Where C2 = log2(C).
- Similarly for (A & C) == 0. */
-
- /* If INNER is a right shift of a constant and it plus BITNUM does
- not overflow, adjust BITNUM and INNER. */
- if (TREE_CODE (inner) == RSHIFT_EXPR
- && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
- && bitnum < TYPE_PRECISION (type)
- && wi::ltu_p (wi::to_wide (TREE_OPERAND (inner, 1)),
- TYPE_PRECISION (type) - bitnum))
- {
- bitnum += tree_to_uhwi (TREE_OPERAND (inner, 1));
- inner = TREE_OPERAND (inner, 0);
- }
-
- /* If we are going to be able to omit the AND below, we must do our
- operations as unsigned. If we must use the AND, we have a choice.
- Normally unsigned is faster, but for some machines signed is. */
- ops_unsigned = (load_extend_op (operand_mode) == SIGN_EXTEND
- && !flag_syntax_only) ? 0 : 1;
-
- signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
- unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
- intermediate_type = ops_unsigned ? unsigned_type : signed_type;
- inner = fold_convert_loc (loc, intermediate_type, inner);
-
- if (bitnum != 0)
- inner = build2 (RSHIFT_EXPR, intermediate_type,
- inner, size_int (bitnum));
-
- one = build_int_cst (intermediate_type, 1);
-
- if (code == EQ_EXPR)
- inner = fold_build2_loc (loc, BIT_XOR_EXPR, intermediate_type, inner, one);
-
- /* Put the AND last so it can combine with more things. */
- inner = build2 (BIT_AND_EXPR, intermediate_type, inner, one);
-
- /* Make sure to return the proper type. */
- inner = fold_convert_loc (loc, result_type, inner);
-
- return inner;
- }
- return NULL_TREE;
-}
-
/* Test whether it is preferable to swap two operands, ARG0 and
ARG1, for example because ARG0 is an integer constant and ARG1
isn't. */
diff --git a/gcc/fold-const.h b/gcc/fold-const.h
index b828badc42f..24c50fcc557 100644
--- a/gcc/fold-const.h
+++ b/gcc/fold-const.h
@@ -92,7 +92,6 @@ extern bool fold_convertible_p (const_tree, const_tree);
#define fold_convert(T1,T2)\
fold_convert_loc (UNKNOWN_LOCATION, T1, T2)
extern tree fold_convert_loc (location_t, tree, tree);
-extern tree fold_single_bit_test (location_t, enum tree_code, tree, tree, tree);
extern tree fold_ignored_result (tree);
extern tree fold_abs_const (tree, tree);
extern tree fold_indirect_ref_1 (location_t, tree, tree);
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