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[GISEL] G_SPLAT_VECTOR can take a splat that is larger than the vector element #86974

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Merged
merged 4 commits into from
Apr 1, 2024
Merged

[GISEL] G_SPLAT_VECTOR can take a splat that is larger than the vector element #86974

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52415ec
[GISEL] G_SPLAT_VECTOR can take a splat that is smaller than the vect…
michaelmaitland Mar 28, 2024
4c615b5
fixup! add break statement
michaelmaitland Mar 28, 2024
cc90e00
fixup! fix description of opcode
michaelmaitland Mar 28, 2024
d2175f8
fixup! use getElementType
michaelmaitland Mar 29, 2024
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4 changes: 4 additions & 0 deletions llvm/docs/GlobalISel/GenericOpcode.rst
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Expand Up @@ -690,6 +690,10 @@ G_SPLAT_VECTOR

Create a vector where all elements are the scalar from the source operand.

The type of the operand must be equal to or larger than the vector element
type. If the operand is larger than the vector element type, the scalar is
implicitly truncated to the vector element type.
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extended?

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I got it all backwards 😆 . The operand should be allowed to be greater than the size of the vector element.


Vector Reduction Operations
---------------------------

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17 changes: 12 additions & 5 deletions llvm/lib/CodeGen/MachineVerifier.cpp
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Expand Up @@ -1768,16 +1768,23 @@ void MachineVerifier::verifyPreISelGenericInstruction(const MachineInstr *MI) {
LLT DstTy = MRI->getType(MI->getOperand(0).getReg());
LLT SrcTy = MRI->getType(MI->getOperand(1).getReg());

if (!DstTy.isScalableVector())
if (!DstTy.isScalableVector()) {
report("Destination type must be a scalable vector", MI);
break;
}

if (!SrcTy.isScalar())
if (!SrcTy.isScalar()) {
report("Source type must be a scalar", MI);
break;
}

if (DstTy.getScalarType() != SrcTy)
report("Element type of the destination must be the same type as the "
"source type",
if (TypeSize::isKnownGT(DstTy.getElementType().getSizeInBits(),
SrcTy.getSizeInBits())) {
report("Element type of the destination must be the same size or smaller "
"than the source type",
MI);
break;
}

break;
}
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4 changes: 2 additions & 2 deletions llvm/test/MachineVerifier/test_g_splat_vector.mir
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Expand Up @@ -22,6 +22,6 @@ body: |
; CHECK: Source type must be a scalar
%6:_(<vscale x 2 x s32>) = G_SPLAT_VECTOR %2

; CHECK: Element type of the destination must be the same type as the source type
%7:_(<vscale x 2 x s64>) = G_SPLAT_VECTOR %0
; CHECK: Element type of the destination must be the same size or smaller than the source type
%7:_(<vscale x 2 x s128>) = G_SPLAT_VECTOR %0
...