[LLVMdev] vector compare

[Claudio Basile]

Hi all,

is there any way to compare two 128bit values?
I have tried 3 different approaches and they all fail with an internal  
assertion.
I'm running llvm 2.4 on x86 with the following command line:

 > llvm-as test.ll -o test.bc
 > llc test.bc -filetype=asm

I would expect the code generator to emit a sequence of SSE  
instructions.

---------------------------------------------------------------------------------------

Approach 1
----------------

define i1 @VectorCompare1(<4 x i32> %x, <4 x i32> %y) {
     %1 = icmp eq <4 x i32> %x, %y
     %2 = bitcast <4 x i1> %1 to i4
     %3 = icmp eq i4 %2, 0
     ret i1 %3
}

This fails with:

ssertion failed: (VT.getSizeInBits() ==  
Operand.getValueType().getSizeInBits() && "Cannot BIT_CONVERT between  
types of different sizes!"), function getNode, file SelectionDAG.cpp,  
line 2218.


Approach 2
----------------

define i1 @VectorCompare2(<4 x i32> %x, <4 x i32> %y) {
     %1 = icmp eq <4 x i32> %x, %y
     %2 = extractelement <4 x i1> %1, i32 0
     %3 = extractelement <4 x i1> %1, i32 1
     %4 = extractelement <4 x i1> %1, i32 2
     %5 = extractelement <4 x i1> %1, i32 3
     %6 = or i1 %2, %3
     %7 = or i1 %4, %5
     %8 = or i1 %6, %7
     ret i1 %8
}

This fails with:

Assertion failed: (isVector() && "Invalid vector type!"), function  
getVectorNumElements, file /Users/cbasile/src/llvm-2.4/include/llvm/ 
CodeGen/ValueTypes.h, line 339.


Approach 3
----------------

define i1 @VectorCompare3(i128 %x, i128 %y) {
     %1 = icmp eq i128 %x, %y
     ret i1 %1
}

This fails with:

Cannot yet select: 0x10182b4: i8 = setcc 0x101844c, 0x10184d4, 0x100becc

---------------------------------------------------------------------------------------

I'd really appreciate if someone could help me with this.

Thanks
Claudio