x86 sse4.2 popCnt16# needs to zero-extend its result

make TEST=cgrun071 EXTRA_HC_OPTS=-msse42 fails for me in all the non-ghci non-llvm ways.

For popCnt16# we emit popcnt %ax,%ax which doesn't clear the high 48 bits of the result.

Patch incoming.

Trac metadata

Trac field	Value
Version	7.9
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler (NCG)
Test case
Differential revisions
BlockedBy
Related
Blocking
CC	simonmar, tibbe
Operating system
Architecture

changed weight to 5

added NCG backend Tbug Trac import labels

popCnt8# is affected too, but (possibly by luck, possibly not) we reuse the source register as the destination register and we needed to zero-extend the source anyways as there is no 8-bit popcnt instruction.

Trac metadata

Trac field	Value
Differential revisions	→ D147

mentioned in commit 64151913

Marking as "merge" per hvr's suggestion.

added 1 deleted label

closed

changed milestone to %7.8.4

Merged to 7.8.4.

Trac metadata

Trac field	Value
Resolution	Unresolved → ResolvedFixed

removed 1 deleted label

added incorrect runtime result label

added Pnormal label