tree d6ff24cd971d09bed11febd9a91d0610a253f241
parent c45c701315afb5d0e6e5972695e438975d4fcd8c
author Nicolas Capens <capn@google.com> 1661881934 -0400
committer Nicolas Capens <nicolascapens@google.com> 1661968237 +0000

Fix Frexp() for subnormal arguments under DAZ

Previously only an all-zero exponent and mantissa field was considered
equal to zero. When denormals-are-zero mode (DAZ) is enabled, currently
the default, we should treat subnormals as zero as well. This is
accomplished using a floating- point compare operation instead of
integer comparison.

Note that, just like the previous implementation, this still does not
handle subnormals correctly when DAZ mode is not enabled. To return a
significand in the range [0.5, 1.0) it will have to support returning
an exponent smaller than -126.

Bug: b/243791551
Bug: b/169904252
Change-Id: I67b7a5a8e971a0290aa5cedb55acae6e70f9485c
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/67828
Kokoro-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>
Tested-by: Nicolas Capens <nicolascapens@google.com>