Summary:
When the RHS of a conditional move node is zero, we can utilize the $zero
register by inverting the conditional move instruction and by swapping the
order of its True/False operands.
Reviewers: dsanders
Differential Revision: http://reviews.llvm.org/D7945
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230956 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
On MIPS32r6/MIPS64r6, floating point comparisons return 0 or -1 but integer
comparisons return 0 or 1.
Updated the various uses of getBooleanContents. Two simplifications had to be
disabled when float and int boolean contents differ:
- ScalarizeVecRes_VSELECT except when the kind of boolean contents is trivially
discoverable (i.e. when the condition of the VSELECT is a SETCC node).
- visitVSELECT (select C, 0, 1) -> (xor C, 1).
Come to think of it, this one could test for the common case of 'C'
being a SETCC too.
Preserved existing behaviour for all other targets and updated the affected
MIPS32r6/MIPS64r6 tests. This also fixes the pi benchmark where the 'low'
variable was counting in the wrong direction because it thought it could simply
add the result of the comparison.
Reviewers: hfinkel
Reviewed By: hfinkel
Subscribers: hfinkel, jholewinski, mcrosier, llvm-commits
Differential Revision: http://reviews.llvm.org/D4389
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212697 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
c.cond.fmt has been replaced by cmp.cond.fmt. Where c.cond.fmt wrote to
dedicated condition registers, cmp.cond.fmt writes 1 or 0 to normal FGR's
(like the GPR comparisons).
mov[fntz] have been replaced by seleqz and selnez. These instructions
conditionally zero a register based on a bool in a GPR. The results can
then be or'd together to act as a select without, for example, requiring a third
register read port.
mov[fntz].[ds] have been replaced with sel.[ds]
MIPS64r6 currently generates unnecessary sign-extensions for most selects.
This is because the result of a SETCC is currently an i32. Bits 32-63 are
undefined in i32 and the behaviour of seleqz/selnez would otherwise depend
on undefined bits. Later, we will fix this by making the result of SETCC an
i64 on MIPS64 targets.
Depends on D3958
Reviewers: jkolek, vmedic, zoran.jovanovic
Reviewed By: vmedic, zoran.jovanovic
Differential Revision: http://reviews.llvm.org/D4003
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210777 91177308-0d34-0410-b5e6-96231b3b80d8
