[llvm-commits] patch: fix emission of npot vectors which need trailing padding

[Nick Lewycky]

Hi! This patch fixes an inconsistency that manifests like this:

typedef float float3 __attribute__((ext_vector_type(3)));

struct Foo {
  float3 x;
  float3 y;
};

struct Foo foo = { {0, 0, 0}, {1, 2, 3} };


This lowers to a struct with <3 x float>, which TargetData says is 16 bytes
on ARM. In LLVM IR, the first element becomes a constant aggregate zero,
which is emitted by looking at how many bytes it is (sixteen) and writing
out a zero-fill. The second element is emitted as three contiguous elements,
resulting in a total of 12 bytes.

The StructLayout object claims that each of those should be 16 bytes, so I
changed the AsmPrinter in CodeGen to apply padding to the end of an array to
match what TargetData thinks the length of the array is. Patch attached,
please review!

Nick
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