If the ++ or -- operator is used on a bitfield, the addition or
subtraction is done with the size of the bitfield. So code like:
struct {
int f:3;
} s;
...
s->f++;
will generate intermediate code like:
add.3 %r <- %a, $1
This is not incorrect from the IR point of view but CPUs have
only register-sized instructions, like 'add.32'. So, these
odd-sized instruction have one or two implicit masking/extend
that should better make explicit.
Fix this by casting to and from the base type when these operators
are used on bitfields.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx>
---
linearize.c | 6 +-
validation/linear/bitfield-inc.c | 1 -
validation/linear/bitfield-size.c | 142 ++++++++++++++++--------------
3 files changed, 80 insertions(+), 69 deletions(-)
diff --git a/linearize.c b/linearize.c
index 9a6fd250a..3cb44847d 100644
--- a/linearize.c
+++ b/linearize.c
@@ -1119,7 +1119,11 @@ static pseudo_t linearize_inc_dec(struct entrypoint *ep, struct expression *expr
one = add_setfval(ep, expr->ctype, expr->op_value);
else
one = value_pseudo(expr->op_value);
- new = add_binary_op(ep, expr->ctype, op, old, one);
+ if (ad.btype != ad.type)
+ old = cast_pseudo(ep, old, ad.type, ad.btype);
+ new = add_binary_op(ep, ad.btype, op, old, one);
+ if (ad.btype != ad.type)
+ new = cast_pseudo(ep, new, ad.btype, ad.type);
linearize_store_gen(ep, new, &ad);
return postop ? old : new;
}
diff --git a/validation/linear/bitfield-inc.c b/validation/linear/bitfield-inc.c
index ed8efe7d7..56997592e 100644
--- a/validation/linear/bitfield-inc.c
+++ b/validation/linear/bitfield-inc.c
@@ -10,7 +10,6 @@ void inc(struct s *p)
/*
* check-name: bitfield-inc
* check-command: test-linearize -Wno-decl $file
- * check-known-to-fail
*
* check-output-ignore
* check-output-excludes: add\\.5
diff --git a/validation/linear/bitfield-size.c b/validation/linear/bitfield-size.c
index 7f9725f9d..841bdd0a6 100644
--- a/validation/linear/bitfield-size.c
+++ b/validation/linear/bitfield-size.c
@@ -49,41 +49,45 @@ upostinc:
load.64 %r1 <- 0[x]
load.32 %r2 <- 0[%r1]
trunc.3 %r3 <- (32) %r2
- add.3 %r4 <- %r3, $1
- load.32 %r5 <- 0[%r1]
- zext.32 %r6 <- (3) %r4
- and.32 %r7 <- %r5, $0xfffffff8
- or.32 %r8 <- %r7, %r6
- store.32 %r8 -> 0[%r1]
- zext.32 %r9 <- (3) %r3
- phisrc.32 %phi1(return) <- %r9
+ zext.32 %r4 <- (3) %r3
+ add.32 %r5 <- %r4, $1
+ trunc.3 %r6 <- (32) %r5
+ load.32 %r7 <- 0[%r1]
+ zext.32 %r8 <- (3) %r6
+ and.32 %r9 <- %r7, $0xfffffff8
+ or.32 %r10 <- %r9, %r8
+ store.32 %r10 -> 0[%r1]
+ zext.32 %r11 <- (3) %r4
+ phisrc.32 %phi1(return) <- %r11
br .L1
.L1:
- phi.32 %r10 <- %phi1(return)
- ret.32 %r10
+ phi.32 %r12 <- %phi1(return)
+ ret.32 %r12
upreinc:
.L2:
<entry-point>
store.64 %arg1 -> 0[x]
- load.64 %r11 <- 0[x]
- load.32 %r12 <- 0[%r11]
- trunc.3 %r13 <- (32) %r12
- add.3 %r14 <- %r13, $1
- load.32 %r15 <- 0[%r11]
- zext.32 %r16 <- (3) %r14
- and.32 %r17 <- %r15, $0xfffffff8
- or.32 %r18 <- %r17, %r16
- store.32 %r18 -> 0[%r11]
- zext.32 %r19 <- (3) %r14
- phisrc.32 %phi2(return) <- %r19
+ load.64 %r13 <- 0[x]
+ load.32 %r14 <- 0[%r13]
+ trunc.3 %r15 <- (32) %r14
+ zext.32 %r16 <- (3) %r15
+ add.32 %r17 <- %r16, $1
+ trunc.3 %r18 <- (32) %r17
+ load.32 %r19 <- 0[%r13]
+ zext.32 %r20 <- (3) %r18
+ and.32 %r21 <- %r19, $0xfffffff8
+ or.32 %r22 <- %r21, %r20
+ store.32 %r22 -> 0[%r13]
+ zext.32 %r23 <- (3) %r18
+ phisrc.32 %phi2(return) <- %r23
br .L3
.L3:
- phi.32 %r20 <- %phi2(return)
- ret.32 %r20
+ phi.32 %r24 <- %phi2(return)
+ ret.32 %r24
ucpy:
@@ -91,15 +95,15 @@ ucpy:
<entry-point>
store.64 %arg1 -> 0[d]
store.64 %arg2 -> 0[s]
- load.64 %r21 <- 0[s]
- load.32 %r22 <- 0[%r21]
- trunc.3 %r23 <- (32) %r22
- load.64 %r24 <- 0[d]
- load.32 %r25 <- 0[%r24]
- zext.32 %r26 <- (3) %r23
- and.32 %r27 <- %r25, $0xfffffff8
- or.32 %r28 <- %r27, %r26
- store.32 %r28 -> 0[%r24]
+ load.64 %r25 <- 0[s]
+ load.32 %r26 <- 0[%r25]
+ trunc.3 %r27 <- (32) %r26
+ load.64 %r28 <- 0[d]
+ load.32 %r29 <- 0[%r28]
+ zext.32 %r30 <- (3) %r27
+ and.32 %r31 <- %r29, $0xfffffff8
+ or.32 %r32 <- %r31, %r30
+ store.32 %r32 -> 0[%r28]
br .L5
.L5:
@@ -110,44 +114,48 @@ spostinc:
.L6:
<entry-point>
store.64 %arg1 -> 0[x]
- load.64 %r29 <- 0[x]
- load.32 %r30 <- 0[%r29]
- trunc.3 %r31 <- (32) %r30
- add.3 %r32 <- %r31, $1
- load.32 %r33 <- 0[%r29]
- zext.32 %r34 <- (3) %r32
- and.32 %r35 <- %r33, $0xfffffff8
- or.32 %r36 <- %r35, %r34
- store.32 %r36 -> 0[%r29]
- zext.32 %r37 <- (3) %r31
- phisrc.32 %phi3(return) <- %r37
+ load.64 %r33 <- 0[x]
+ load.32 %r34 <- 0[%r33]
+ trunc.3 %r35 <- (32) %r34
+ zext.32 %r36 <- (3) %r35
+ add.32 %r37 <- %r36, $1
+ trunc.3 %r38 <- (32) %r37
+ load.32 %r39 <- 0[%r33]
+ zext.32 %r40 <- (3) %r38
+ and.32 %r41 <- %r39, $0xfffffff8
+ or.32 %r42 <- %r41, %r40
+ store.32 %r42 -> 0[%r33]
+ zext.32 %r43 <- (3) %r36
+ phisrc.32 %phi3(return) <- %r43
br .L7
.L7:
- phi.32 %r38 <- %phi3(return)
- ret.32 %r38
+ phi.32 %r44 <- %phi3(return)
+ ret.32 %r44
spreinc:
.L8:
<entry-point>
store.64 %arg1 -> 0[x]
- load.64 %r39 <- 0[x]
- load.32 %r40 <- 0[%r39]
- trunc.3 %r41 <- (32) %r40
- add.3 %r42 <- %r41, $1
- load.32 %r43 <- 0[%r39]
- zext.32 %r44 <- (3) %r42
- and.32 %r45 <- %r43, $0xfffffff8
- or.32 %r46 <- %r45, %r44
- store.32 %r46 -> 0[%r39]
- zext.32 %r47 <- (3) %r42
- phisrc.32 %phi4(return) <- %r47
+ load.64 %r45 <- 0[x]
+ load.32 %r46 <- 0[%r45]
+ trunc.3 %r47 <- (32) %r46
+ zext.32 %r48 <- (3) %r47
+ add.32 %r49 <- %r48, $1
+ trunc.3 %r50 <- (32) %r49
+ load.32 %r51 <- 0[%r45]
+ zext.32 %r52 <- (3) %r50
+ and.32 %r53 <- %r51, $0xfffffff8
+ or.32 %r54 <- %r53, %r52
+ store.32 %r54 -> 0[%r45]
+ zext.32 %r55 <- (3) %r50
+ phisrc.32 %phi4(return) <- %r55
br .L9
.L9:
- phi.32 %r48 <- %phi4(return)
- ret.32 %r48
+ phi.32 %r56 <- %phi4(return)
+ ret.32 %r56
scpy:
@@ -155,15 +163,15 @@ scpy:
<entry-point>
store.64 %arg1 -> 0[d]
store.64 %arg2 -> 0[s]
- load.64 %r49 <- 0[s]
- load.32 %r50 <- 0[%r49]
- trunc.3 %r51 <- (32) %r50
- load.64 %r52 <- 0[d]
- load.32 %r53 <- 0[%r52]
- zext.32 %r54 <- (3) %r51
- and.32 %r55 <- %r53, $0xfffffff8
- or.32 %r56 <- %r55, %r54
- store.32 %r56 -> 0[%r52]
+ load.64 %r57 <- 0[s]
+ load.32 %r58 <- 0[%r57]
+ trunc.3 %r59 <- (32) %r58
+ load.64 %r60 <- 0[d]
+ load.32 %r61 <- 0[%r60]
+ zext.32 %r62 <- (3) %r59
+ and.32 %r63 <- %r61, $0xfffffff8
+ or.32 %r64 <- %r63, %r62
+ store.32 %r64 -> 0[%r60]
br .L11
.L11:
--
2.18.0
--
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