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| author | Luc Van Oostenryck <luc.vanoostenryck@gmail.com> | 2016-12-14 09:55:20 +0100 |
|---|---|---|
| committer | Luc Van Oostenryck <luc.vanoostenryck@gmail.com> | 2017-05-12 01:36:07 +0200 |
| commit | 6217cd5c130071a65c4d30d8e846f9c9ef0a9bd4 (patch) | |
| tree | b5773e1ca69a2bd3b159da6c559d7a473782b66f | |
| parent | e35efe330c6ae7d154197c29b127560d569016d0 (diff) | |
| download | sparse-dev-6217cd5c130071a65c4d30d8e846f9c9ef0a9bd4.tar.gz | |
fix boolean context for OP_AND_BOOL & OP_OR_BOOL
Current simplifications of 'x && 1 --> x' and its dual
'x || 0 --> x' are wrong because the '||' and '&&' operators
demand that their operands are first compared against zero
which then always give a boolean valued result.
For example: '3 && 1' is not equal to '3' but to '1' (or 'true').
The correct simplification is thus 'x && 1 --> x != 0' and
'x || 0 --> x != 0'.
Fix this by always first doing the comparison against zero
before generating the OP_AND_BOOL and OP_OR_BOOL instructions.
Note: of course, we could decide that the semantic of OP_AND_BOOL
and OP_OR_BOOL is that these ops take care themselves of
making a boolean context (which was, I think, why these
ops were created) but then these simplifications cannot be
done (or when they are done, we need to add the comparison
against zero).
Fixes: b85ec4bb7f5b1c522d7c71782dbd9cf1c4c49b2f
Fixes: a0886db12307d2633b04ec44342099a2955794a5
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
| -rw-r--r-- | linearize.c | 37 | ||||
| -rw-r--r-- | validation/optim/bool-context.c | 12 | ||||
| -rw-r--r-- | validation/optim/bool-simplify.c | 8 |
3 files changed, 53 insertions, 4 deletions
diff --git a/linearize.c b/linearize.c index a9f36b82..236d37a3 100644 --- a/linearize.c +++ b/linearize.c @@ -1156,6 +1156,26 @@ static int opcode_sign(int opcode, struct symbol *ctype) return opcode; } +static inline pseudo_t add_convert_to_bool(struct entrypoint *ep, pseudo_t src, struct symbol *type) +{ + pseudo_t zero; + int op; + + if (is_bool_type(type)) + return src; + zero = value_pseudo(0); + op = OP_SET_NE; + return add_binary_op(ep, &bool_ctype, op, src, zero); +} + +static pseudo_t linearize_expression_to_bool(struct entrypoint *ep, struct expression *expr) +{ + pseudo_t dst; + dst = linearize_expression(ep, expr); + dst = add_convert_to_bool(ep, dst, expr->ctype); + return dst; +} + static pseudo_t linearize_assignment(struct entrypoint *ep, struct expression *expr) { struct access_data ad = { NULL, }; @@ -1276,6 +1296,19 @@ static pseudo_t linearize_call_expression(struct entrypoint *ep, struct expressi return retval; } +static pseudo_t linearize_binop_bool(struct entrypoint *ep, struct expression *expr) +{ + pseudo_t src1, src2, dst; + int op = (expr->op == SPECIAL_LOGICAL_OR) ? OP_OR_BOOL : OP_AND_BOOL; + + src1 = linearize_expression_to_bool(ep, expr->left); + src2 = linearize_expression_to_bool(ep, expr->right); + dst = add_binary_op(ep, &bool_ctype, op, src1, src2); + if (expr->ctype != &bool_ctype) + dst = cast_pseudo(ep, dst, &bool_ctype, expr->ctype); + return dst; +} + static pseudo_t linearize_binop(struct entrypoint *ep, struct expression *expr) { pseudo_t src1, src2, dst; @@ -1286,8 +1319,6 @@ static pseudo_t linearize_binop(struct entrypoint *ep, struct expression *expr) ['|'] = OP_OR, ['^'] = OP_XOR, [SPECIAL_LEFTSHIFT] = OP_SHL, [SPECIAL_RIGHTSHIFT] = OP_LSR, - [SPECIAL_LOGICAL_AND] = OP_AND_BOOL, - [SPECIAL_LOGICAL_OR] = OP_OR_BOOL, }; int op; @@ -1570,6 +1601,8 @@ pseudo_t linearize_expression(struct entrypoint *ep, struct expression *expr) return linearize_call_expression(ep, expr); case EXPR_BINOP: + if (expr->op == SPECIAL_LOGICAL_AND || expr->op == SPECIAL_LOGICAL_OR) + return linearize_binop_bool(ep, expr); return linearize_binop(ep, expr); case EXPR_LOGICAL: diff --git a/validation/optim/bool-context.c b/validation/optim/bool-context.c new file mode 100644 index 00000000..11326d39 --- /dev/null +++ b/validation/optim/bool-context.c @@ -0,0 +1,12 @@ +#define bool _Bool + +bool bool_ior(int a, int b) { return a || b; } +bool bool_and(int a, int b) { return a && b; } + +/* + * check-name: bool-context + * check-command: test-linearize -Wno-decl $file + * check-output-ignore + * + * check-output-pattern-4-times: setne\\..* %arg[12] + */ diff --git a/validation/optim/bool-simplify.c b/validation/optim/bool-simplify.c index e0ff1c2d..05be1149 100644 --- a/validation/optim/bool-simplify.c +++ b/validation/optim/bool-simplify.c @@ -32,13 +32,17 @@ and_0: and_1: .L2: <entry-point> - ret.32 %arg1 + setne.1 %r8 <- %arg1, $0 + cast.32 %r11 <- (1) %r8 + ret.32 %r11 or_0: .L4: <entry-point> - ret.32 %arg1 + setne.1 %r14 <- %arg1, $0 + cast.32 %r17 <- (1) %r14 + ret.32 %r17 or_1: |