On Thu, 8 May 2014 15:16:26 -0700, Charles Mills wrote:
>Am I missing something here? Consider the following C statement:
>
>unsigned long long maxBit = 0x1 << (arraySize-3);
>
>When arraySize is 66, maxBit is ending up as zero (instead of what I would
>expect, X'8000000000000000'. Am I missing something?
>
>Here is the LIST output. (No optimization.)
>
>* unsigned long long maxBit = 0x1 << (arraySize-3);
> EX r0,HOOK..STMT
> L r1,arraySize(,r13,240)
> AHI r1,H'-3'
> LA r2,1
> LR r0,r2
> SLL r0,0(r1)
> LR r1,r0
> SRA r1,31
> ST r1,maxBit(,r13,248)
> ST r0,maxBit(,r13,252)
>
>Won't SLL R0,0(R1) yield a zero for any shift values greater than 31?
>
Does it work better with a cast:
unsigned long long maxBit = (long long) 0x1 << (arraySize-3);?
I might then expect:
SLDL r0,0(r1)
-- gil
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