codegen assertion on i960 value

[lattner]

Bugzilla Link	3450
Resolution	DUPLICATE
Resolved on	Jan 31, 2009 02:45
Version	1.0
OS	All
Attachments	testcase
CC	@sunfishcode

Extended Description

Benchmarks/McCat/08-main is now failing because SROA makes an i960 and codegen can't handle it:

SelectionDAG.cpp:863: failed assertion `(EltVT.getSizeInBits() >= 64 || (uint64_t)((int64_t)Val >> EltVT.getSizeInBits()) + 1 < 2) && "getConstant with a uint64_t value that doesn't fit in the type!"'

This is dying in SelectionDAG::getConstant

[lattner]

This problem is occuring in SelectionDAGBuild.cpp:590:

588 SDValue OddVal = DAG.getNode(ISD::SRL, dl, ValueVT, Val,
589 DAG.getConstant(RoundBits,
590 TLI.getShiftAmountTy()));

It needs a shift amount of 512, but getShiftAmountTy is only i8.

[lattner]

this also affects MultiSource/Benchmarks/MallocBench/gs, 447.dealII, clamscan, 188.ammp etc.

Instcombine is missing an xform here that will cover at least partially for this problem, but we really should come up with a solution.

[llvmbot]

*** This bug has been marked as a duplicate of bug #3773 ***

[lattner]

Note that the r63481 instcombine patch works around the crash, at least in 08-main.