This reverts commit 69fcfb7d35.
As shown in the test I attached to this commit, the change I reverted
causes a problem with "zext(cc1) - zext(cc2)". It commuted
the operands to the sub and used different logic to select the addc/subc
instruction:
sub zext (setcc), x => addcarry 0, x, setcc
sub sext (setcc), x => subcarry 0, x, setcc
... but that is bogus. I believe it is not possible to fold those commuted
patterns into any form of addcarry or subcarry. It may have worked as
intended before "AMDGPU: Change boolean content type to 0 or 1" because
the setcc was considered to be -1 rather than 1.
Differential Revision: https://reviews.llvm.org/D70978
Change-Id: If2139421aa6c935cbd1d925af58fe4a4aa9e8f43
The usage of target boolean checks is overly inflexible, since sext
and zext of a compare are equally cheap. The choice is arbitrary, but
using 0/1 to some degree is the choice of lower resistance since
that's what most targets use. This enables a few combines that don't
bother to support ZeroOrNegativeOneBooleanContent.
Summary: performAddCombine should run after DAG is legalized; Otherwise generic optimization
in the DAGCombiner can optimize an addcarry+trunc into an addcarry instruction with
illegal types.
Author: FarhanaAleen
Reviewed By: rampitec
Subscribers: llvm-commits, AMDGPU
Differential Revision: https://reviews.llvm.org/D46337
llvm-svn: 331368
V_SUBBREV_U32 is a commute opcode for V_SUBB_U32. However, when
we try to commute V_SUBB_U32 in order to shrink it we do not then
process V_SUBBREV_U32 and it stay VOP3. This is fixed.
Differential Revision: https://reviews.llvm.org/D43699
llvm-svn: 326011
Also factored out function to check if a boolean is an already
deserialized value which does not require v_cndmask_b32 to be
loaded. Added binary logical operators to its check.
Differential Revision: https://reviews.llvm.org/D34500
llvm-svn: 306439
If one of the arguments of adde/sube is zero we can fold another
add/sub into it.
Differential Revision: https://reviews.llvm.org/D34374
llvm-svn: 305964
This simplification allows to avoid generating v_cndmask_b32
to serialize condition code between compare and use.
Differential Revision: https://reviews.llvm.org/D34300
llvm-svn: 305962
Tim Renouf