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fix(compiler): wrap RHS shifting value by maximum size of type in bits for small integers #1511

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Merged
merged 5 commits into from
Oct 20, 2020
Merged

fix(compiler): wrap RHS shifting value by maximum size of type in bits for small integers #1511

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815f97a
init
MaxGraey Oct 19, 2020
f2d4786
comments
MaxGraey Oct 19, 2020
96f74ef
skip wrapping LHS for booleans
MaxGraey Oct 19, 2020
e5f071b
new comments
MaxGraey Oct 19, 2020
d652847
for boolean simply return LHS
MaxGraey Oct 19, 2020
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56 changes: 33 additions & 23 deletions src/compiler.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -5128,7 +5128,7 @@ export class Compiler extends DiagnosticEmitter {
module.binary(BinaryOp.EqI8x16, leftExpr, rightExpr)
);
}
case TypeKind.FUNCREF:
case TypeKind.FUNCREF:
case TypeKind.EXTERNREF:
case TypeKind.EXNREF:
case TypeKind.ANYREF: {
Expand Down Expand Up @@ -5641,14 +5641,18 @@ export class Compiler extends DiagnosticEmitter {
// Cares about garbage bits on the RHS, but only for types smaller than 5 bits
var module = this.module;
switch (type.kind) {
case TypeKind.BOOL: {
rightExpr = this.ensureSmallIntegerWrap(rightExpr, type);
// falls through
}
case TypeKind.BOOL: return leftExpr;
case TypeKind.I8:
case TypeKind.I16:
case TypeKind.U8:
case TypeKind.U16:
case TypeKind.U16: {
// leftExpr << (rightExpr & (7|15))
return module.binary(
BinaryOp.ShlI32,
leftExpr,
module.binary(BinaryOp.AndI32, rightExpr, module.i32(type.size - 1))
);
}
case TypeKind.I32:
case TypeKind.U32: {
return module.binary(BinaryOp.ShlI32, leftExpr, rightExpr);
Expand Down Expand Up @@ -5677,10 +5681,24 @@ export class Compiler extends DiagnosticEmitter {
// and signedness
var module = this.module;
switch (type.kind) {
case TypeKind.BOOL: return leftExpr;
case TypeKind.I8:
case TypeKind.I16: {
leftExpr = this.ensureSmallIntegerWrap(leftExpr, type);
// falls through
// leftExpr >> (rightExpr & (7|15))
return module.binary(
BinaryOp.ShrI32,
this.ensureSmallIntegerWrap(leftExpr, type),
module.binary(BinaryOp.AndI32, rightExpr, module.i32(type.size - 1))
);
}
case TypeKind.U8:
case TypeKind.U16: {
// leftExpr >>> (rightExpr & (7|15))
return module.binary(
BinaryOp.ShrU32,
this.ensureSmallIntegerWrap(leftExpr, type),
module.binary(BinaryOp.AndI32, rightExpr, module.i32(type.size - 1))
);
}
case TypeKind.I32: {
return module.binary(BinaryOp.ShrI32, leftExpr, rightExpr);
Expand All @@ -5697,15 +5715,6 @@ export class Compiler extends DiagnosticEmitter {
rightExpr
);
}
case TypeKind.BOOL: {
rightExpr = this.ensureSmallIntegerWrap(rightExpr, type);
// falls through
}
case TypeKind.U8:
case TypeKind.U16: {
leftExpr = this.ensureSmallIntegerWrap(leftExpr, type);
// falls through
}
case TypeKind.U32: {
return module.binary(BinaryOp.ShrU32, leftExpr, rightExpr);
}
Expand All @@ -5730,16 +5739,17 @@ export class Compiler extends DiagnosticEmitter {
// Cares about garbage bits on the LHS, but on the RHS only for types smaller than 5 bits
var module = this.module;
switch (type.kind) {
case TypeKind.BOOL: {
rightExpr = this.ensureSmallIntegerWrap(rightExpr, type);
// falls through
}
case TypeKind.BOOL: return leftExpr;
case TypeKind.I8:
case TypeKind.I16:
case TypeKind.U8:
case TypeKind.U16: {
leftExpr = this.ensureSmallIntegerWrap(leftExpr, type);
// falls through
// leftExpr >>> (rightExpr & (7|15))
return module.binary(
BinaryOp.ShrU32,
this.ensureSmallIntegerWrap(leftExpr, type),
module.binary(BinaryOp.AndI32, rightExpr, module.i32(type.size - 1))
);
}
case TypeKind.I32:
case TypeKind.U32: {
Expand Down
2 changes: 2 additions & 0 deletions tests/compiler/abi.untouched.wat
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Original file line number Diff line number Diff line change
Expand Up @@ -88,6 +88,8 @@
i32.const 24
i32.shr_s
i32.const 24
i32.const 7
i32.and
i32.shr_s
local.set $0
else
Expand Down
4 changes: 2 additions & 2 deletions tests/compiler/retain-i32.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -7,7 +7,7 @@ function test(a: u32, b: u32): void {
assert(<i8>(a & b) == <i8>(<i8>a & <i8>b));
assert(<i8>(a | b) == <i8>(<i8>a | <i8>b));
assert(<i8>(a ^ b) == <i8>(<i8>a ^ <i8>b));
assert(<i8>(a << b) == <i8>(<i8>a << <i8>b));
assert(<i8>(a << (b & 7)) == <i8>(<i8>a << <i8>b));

// unsigned
assert(<u8>(a + b) == <u8>(<u8>a + <u8>b));
Expand All @@ -16,7 +16,7 @@ function test(a: u32, b: u32): void {
assert(<u8>(a & b) == <u8>(<u8>a & <u8>b));
assert(<u8>(a | b) == <u8>(<u8>a | <u8>b));
assert(<u8>(a ^ b) == <u8>(<u8>a ^ <u8>b));
assert(<u8>(a << b) == <u8>(<u8>a << <u8>b));
assert(<u8>(a << (b & 7)) == <u8>(<u8>a << <u8>b));
}

// signed
Expand Down
8 changes: 8 additions & 0 deletions tests/compiler/retain-i32.untouched.wat
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Original file line number Diff line number Diff line change
Expand Up @@ -167,13 +167,17 @@
end
local.get $0
local.get $1
i32.const 7
i32.and
i32.shl
i32.const 24
i32.shl
i32.const 24
i32.shr_s
local.get $0
local.get $1
i32.const 7
i32.and
i32.shl
i32.const 24
i32.shl
Expand Down Expand Up @@ -311,11 +315,15 @@
end
local.get $0
local.get $1
i32.const 7
i32.and
i32.shl
i32.const 255
i32.and
local.get $0
local.get $1
i32.const 7
i32.and
i32.shl
i32.const 255
i32.and
Expand Down
8 changes: 8 additions & 0 deletions tests/compiler/std/dataview.untouched.wat
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Original file line number Diff line number Diff line change
Expand Up @@ -2124,13 +2124,17 @@
drop
local.get $0
i32.const 8
i32.const 15
i32.and
i32.shl
local.get $0
i32.const 16
i32.shl
i32.const 16
i32.shr_s
i32.const 8
i32.const 15
i32.and
i32.shr_s
i32.const 255
i32.and
Expand Down Expand Up @@ -2344,11 +2348,15 @@
drop
local.get $0
i32.const 8
i32.const 15
i32.and
i32.shl
local.get $0
i32.const 65535
i32.and
i32.const 8
i32.const 15
i32.and
i32.shr_u
i32.const 255
i32.and
Expand Down
16 changes: 16 additions & 0 deletions tests/compiler/std/polyfills.untouched.wat
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Original file line number Diff line number Diff line change
Expand Up @@ -54,11 +54,15 @@
drop
local.get $0
i32.const 8
i32.const 15
i32.and
i32.shl
local.get $0
i32.const 65535
i32.and
i32.const 8
i32.const 15
i32.and
i32.shr_u
i32.const 255
i32.and
Expand All @@ -74,13 +78,17 @@
drop
local.get $0
i32.const 8
i32.const 15
i32.and
i32.shl
local.get $0
i32.const 16
i32.shl
i32.const 16
i32.shr_s
i32.const 8
i32.const 15
i32.and
i32.shr_s
i32.const 255
i32.and
Expand Down Expand Up @@ -347,11 +355,15 @@
drop
local.get $0
i32.const 8
i32.const 15
i32.and
i32.shl
local.get $0
i32.const 65535
i32.and
i32.const 8
i32.const 15
i32.and
i32.shr_u
i32.const 255
i32.and
Expand All @@ -374,13 +386,17 @@
drop
local.get $0
i32.const 8
i32.const 15
i32.and
i32.shl
local.get $0
i32.const 16
i32.shl
i32.const 16
i32.shr_s
i32.const 8
i32.const 15
i32.and
i32.shr_s
i32.const 255
i32.and
Expand Down