[PATCH] D126953: Promote bf16 to f32 when the target doesn't support it

[Craig Topper via Phabricator via llvm-commits]

craig.topper added a comment.

In D126953#3986425 <https://reviews.llvm.org/D126953#3986425>, @lebedev.ri wrote:

> FWIW, i agree with @arsenm, the legalization is wrong.

The lowering is correct. Mantissa for ieee numbers are normalized by shifting left to avoid storing the first 1.

Consider the number 1.5. In f32 it is stored as 0x3fc00000
sign = 0
exponent = 127
mantissa = 0x400000

1.5 in bfloat16 is 0x3fc0
sign = 0
exponent = 127
mantissa = 0x400


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https://reviews.llvm.org/D126953