2017-01-25 06:02:15 +08:00
|
|
|
; RUN: llc -march=amdgcn -verify-machineinstrs < %s | FileCheck -check-prefix=SI %s
|
2015-01-28 01:27:15 +08:00
|
|
|
; RUN: llc -march=amdgcn -mcpu=tonga -verify-machineinstrs < %s | FileCheck -check-prefix=SI %s
|
2014-10-22 13:30:42 +08:00
|
|
|
|
2014-11-19 05:06:58 +08:00
|
|
|
; SI-LABEL: {{^}}br_i1_phi:
|
AMDGPU: Rewrite SILowerI1Copies to always stay on SALU
Summary:
Instead of writing boolean values temporarily into 32-bit VGPRs
if they are involved in PHIs or are observed from outside a loop,
we use bitwise masking operations to combine lane masks in a way
that is consistent with wave control flow.
Move SIFixSGPRCopies to before this pass, since that pass
incorrectly attempts to move SGPR phis to VGPRs.
This should recover most of the code quality that was lost with
the bug fix in "AMDGPU: Remove PHI loop condition optimization".
There are still some relevant cases where code quality could be
improved, in particular:
- We often introduce redundant masks with EXEC. Ideally, we'd
have a generic computeKnownBits-like analysis to determine
whether masks are already masked by EXEC, so we can avoid this
masking both here and when lowering uniform control flow.
- The criterion we use to determine whether a def is observed
from outside a loop is conservative: it doesn't check whether
(loop) branch conditions are uniform.
Change-Id: Ibabdb373a7510e426b90deef00f5e16c5d56e64b
Reviewers: arsenm, rampitec, tpr
Subscribers: kzhuravl, jvesely, wdng, mgorny, yaxunl, dstuttard, t-tye, eraman, llvm-commits
Differential Revision: https://reviews.llvm.org/D53496
llvm-svn: 345719
2018-10-31 21:27:08 +08:00
|
|
|
|
|
|
|
|
; SI: ; %bb
|
|
|
|
|
; SI: s_mov_b64 [[TMP:s\[[0-9]+:[0-9]+\]]], 0
|
|
|
|
|
|
|
|
|
|
; SI: ; %bb2
|
|
|
|
|
; SI: s_mov_b64 [[TMP]], exec
|
|
|
|
|
|
|
|
|
|
; SI: ; %bb3
|
|
|
|
|
; SI: s_and_saveexec_b64 {{s\[[0-9]+:[0-9]+\]}}, [[TMP]]
|
|
|
|
|
|
2017-03-22 05:39:51 +08:00
|
|
|
define amdgpu_kernel void @br_i1_phi(i32 %arg) {
|
2014-10-22 13:30:42 +08:00
|
|
|
bb:
|
2017-05-18 05:38:21 +08:00
|
|
|
%tidig = call i32 @llvm.amdgcn.workitem.id.x()
|
2016-02-13 07:45:29 +08:00
|
|
|
%cmp = trunc i32 %tidig to i1
|
|
|
|
|
br i1 %cmp, label %bb2, label %bb3
|
2014-10-22 13:30:42 +08:00
|
|
|
|
|
|
|
|
bb2: ; preds = %bb
|
|
|
|
|
br label %bb3
|
|
|
|
|
|
|
|
|
|
bb3: ; preds = %bb2, %bb
|
|
|
|
|
%tmp = phi i1 [ true, %bb2 ], [ false, %bb ]
|
|
|
|
|
br i1 %tmp, label %bb4, label %bb6
|
|
|
|
|
|
|
|
|
|
bb4: ; preds = %bb3
|
2016-05-18 23:48:44 +08:00
|
|
|
%val = load volatile i32, i32 addrspace(1)* undef
|
|
|
|
|
%tmp5 = mul i32 %val, %arg
|
2014-10-22 13:30:42 +08:00
|
|
|
br label %bb6
|
|
|
|
|
|
|
|
|
|
bb6: ; preds = %bb4, %bb3
|
|
|
|
|
ret void
|
|
|
|
|
}
|
2016-02-13 07:45:29 +08:00
|
|
|
|
2017-05-18 05:38:21 +08:00
|
|
|
declare i32 @llvm.amdgcn.workitem.id.x() #0
|
2016-02-13 07:45:29 +08:00
|
|
|
|
2017-05-18 05:38:21 +08:00
|
|
|
attributes #0 = { nounwind readnone }
|
[SelectionDAG] Enhance the simplification of `copyto` from `implicit-def`.
Summary:
- The current implementation simplifies the case where the source of
`copyto` is `implicit-def`ed. However, it only works when that
`implicit-def` is single-used since it detects that from
`implicit-def` and cannot determine which destination vreg should be
used if there are multiple uses.
- This patch changes that detection when `copyto` is being emitted. If
that `copyto`'s source is defined from `implicit-def`, it simplifies
it. Hence, it works even that `implicit-def` is multi-used.
- Except it simplifies the internal IR, it won't improve the quality of
code generation. However, it helps to detect 'implicit-def` in a
straight-forward manner in some passes, such as `si-i1-copies`. A test
case is added.
Reviewers: sunfish, nhaehnle
Subscribers: jvesely, hiraditya, asbirlea, llvm-commits, yaxunl
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62342
llvm-svn: 361777
2019-05-28 02:26:29 +08:00
|
|
|
|
|
|
|
|
; Make sure this won't crash.
|
|
|
|
|
; SI-LABEL: {{^}}vcopy_i1_undef
|
|
|
|
|
; SI: v_cndmask_b32_e64
|
|
|
|
|
; SI: v_cndmask_b32_e64
|
|
|
|
|
define <2 x float> @vcopy_i1_undef(<2 x float> addrspace(1)* %p) {
|
|
|
|
|
entry:
|
|
|
|
|
br i1 undef, label %exit, label %false
|
|
|
|
|
|
|
|
|
|
false:
|
|
|
|
|
%x = load <2 x float>, <2 x float> addrspace(1)* %p
|
|
|
|
|
%cmp = fcmp one <2 x float> %x, zeroinitializer
|
|
|
|
|
br label %exit
|
|
|
|
|
|
|
|
|
|
exit:
|
|
|
|
|
%c = phi <2 x i1> [ undef, %entry ], [ %cmp, %false ]
|
|
|
|
|
%ret = select <2 x i1> %c, <2 x float> <float 2.0, float 2.0>, <2 x float> <float 4.0, float 4.0>
|
|
|
|
|
ret <2 x float> %ret
|
|
|
|
|
}
|