test-unssa.c compiles this:
extern void func(int i, ...);
void foo(int i) { func(0, (float) i, (double) i, i); }
...into this:
fpcast.64 %r3 <- (32) %arg1
scast.64 %r5 <- (32) %arg1
call func, $0, %r3, %r5, %arg1
ret
That's with the default settings. Unfortunately, with Clue,
sizeof(double) == sizeof(int), so that second instruction comes out as:
scast.32 %r5 <- (32) %arg1
This then causes the simplification code in simplify_cast() to discard it:
if (size == orig_size) {
int op = (orig_type->ctype.modifiers & MOD_SIGNED) ? OP_SCAST : OP_CAST;
if (insn->opcode == op)
goto simplify;
}
The end result is that my call statement turns into:
call func, $0, %r3, %arg1, %arg1
...which is wrong.
I assume that Clue's odd configuration is violating some assumption
somewhere, but I'm not well-enough versed with the sparse internals to
know where. It does seem odd to me that it's generating an OP_SCAST to
convert the int to a double, rather than an OP_FPCAST like in the float.
In the mean time, I've commented out the quoted stanza from
simplify_cast() on my setup, which makes things work, but that's not
really very pleasant.
Can anyone shed light on what might be happening here? Could this be a
symptom of some more serious underlying bug?
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