Hi,
I changed the compiler flag -Wno-unused-value to -Wunused-value because there's no reason to carry dead code. Dead code should ring a bell.
it seems it uncovers a problem in code generation.
An example is in code generated for sendInvokeCallbackContext:
if ((argumentCountOfMethodHeader(methodHeaderOf(GIV(newMethod)))) == 4) {
/* begin push: */
value = ((usqInt)((vmCallbackContext->thunkp)));
/* begin positive32BitIntegerFor: */
/* begin maybeInlinePositive32BitIntegerFor: */
assert(!((hasSixtyFourBitImmediates())));
if ((((unsigned int) value)) <= (MaxSmallInteger)) {
((value << 1) | 1);
^~~~~~~~~~~~~~ PROBLEM HERE: this result should be stored in variable 'object'
goto l4;
}
/* begin eeInstantiateSmallClassIndex:format:numSlots: */
...snip...
object = newLargeInteger;
l4: /* end maybeInlinePositive32BitIntegerFor: */;
goto l5;
l5: /* end positive32BitIntegerFor: */;
longAtput((sp = GIV(stackPointer) - BytesPerWord), object);
The corresponding Slang code is:
(self argumentCountOf: newMethod) = 4 ifTrue:
[self push: (self positiveMachineIntegerFor: vmCallbackContext thunkp asUnsignedInteger).
With push:
| sp |
<inline: true>
<var: #sp type: #'char *'>
stackPages longAt: (sp := stackPointer - objectMemory wordSize) put: object.
stackPointer := sp
With positiveMachineIntegerFor:
<var: #value type: #'unsigned long'>
<inline: true>
^objectMemory wordSize = 8
ifTrue: [self positive64BitIntegerFor: value]
ifFalse: [self positive32BitIntegerFor: value]
With positive32BitIntegerFor:
<inline: true>
<var: 'integerValue' type: #'unsigned int'>
objectMemory hasSixtyFourBitImmediates
ifTrue:
[^objectMemory integerObjectOf: (integerValue asUnsignedLong bitAnd: 16rFFFFFFFF)]
ifFalse:
[^self maybeInlinePositive32BitIntegerFor: integerValue]
With maybeInlinePositive32BitIntegerFor:
<notOption: #Spur64BitMemoryManager>
<var: 'integerValue' type: #'unsigned int'>
| newLargeInteger |
self deny: objectMemory hasSixtyFourBitImmediates.
"force coercion because slang inliner sometimes incorrectly pass a signed int without converting to unsigned"
(self cCode: [self cCoerceSimple: integerValue to: #'unsigned int']
inSmalltalk: [integerValue bitAnd: 1 << 32 - 1]) <= objectMemory maxSmallInteger ifTrue:
[^objectMemory integerObjectOf: integerValue].
newLargeInteger := objectMemory
eeInstantiateSmallClassIndex:
...snip...
^newLargeInteger