llvm/test/CodeGen/AMDGPU/sgpr-control-flow.ll
Matt Arsenault 7eba65d30c AMDGPU: Use unsigned compare for eq/ne
For some reason there are both of these available, except
for scalar 64-bit compares which only has u64. I'm not sure
why there are both (I'm guessing it's for the one bit inputs we
don't use), but for consistency always using the
unsigned one.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282832 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-30 01:50:20 +00:00

106 lines
2.9 KiB
LLVM

; RUN: llc -march=amdgcn -verify-machineinstrs< %s | FileCheck -check-prefix=SI %s
;
;
; Most SALU instructions ignore control flow, so we need to make sure
; they don't overwrite values from other blocks.
; If the branch decision is made based on a value in an SGPR then all
; threads will execute the same code paths, so we don't need to worry
; about instructions in different blocks overwriting each other.
; SI-LABEL: {{^}}sgpr_if_else_salu_br:
; SI: s_add
; SI: s_add
define void @sgpr_if_else_salu_br(i32 addrspace(1)* %out, i32 %a, i32 %b, i32 %c, i32 %d, i32 %e) {
entry:
%0 = icmp eq i32 %a, 0
br i1 %0, label %if, label %else
if:
%1 = add i32 %b, %c
br label %endif
else:
%2 = add i32 %d, %e
br label %endif
endif:
%3 = phi i32 [%1, %if], [%2, %else]
%4 = add i32 %3, %a
store i32 %4, i32 addrspace(1)* %out
ret void
}
; The two S_ADD instructions should write to different registers, since
; different threads will take different control flow paths.
; SI-LABEL: {{^}}sgpr_if_else_valu_br:
; SI: s_add_i32 [[SGPR:s[0-9]+]]
; SI-NOT: s_add_i32 [[SGPR]]
define void @sgpr_if_else_valu_br(i32 addrspace(1)* %out, float %a, i32 %b, i32 %c, i32 %d, i32 %e) {
entry:
%tid = call i32 @llvm.amdgcn.workitem.id.x() #0
%tid_f = uitofp i32 %tid to float
%tmp1 = fcmp ueq float %tid_f, 0.0
br i1 %tmp1, label %if, label %else
if:
%tmp2 = add i32 %b, %c
br label %endif
else:
%tmp3 = add i32 %d, %e
br label %endif
endif:
%tmp4 = phi i32 [%tmp2, %if], [%tmp3, %else]
store i32 %tmp4, i32 addrspace(1)* %out
ret void
}
; FIXME: Should write to different SGPR pairs instead of copying to
; VALU for i1 phi.
; SI-LABEL: {{^}}sgpr_if_else_valu_cmp_phi_br:
; SI: buffer_load_dword [[AVAL:v[0-9]+]]
; SI: v_cmp_gt_i32_e32 [[CMP_IF:vcc]], 0, [[AVAL]]
; SI: v_cndmask_b32_e64 [[V_CMP:v[0-9]+]], 0, -1, [[CMP_IF]]
; SI: BB2_2:
; SI: buffer_load_dword [[AVAL:v[0-9]+]]
; SI: v_cmp_eq_u32_e32 [[CMP_ELSE:vcc]], 0, [[AVAL]]
; SI: v_cndmask_b32_e64 [[V_CMP]], 0, -1, [[CMP_ELSE]]
; SI: v_cmp_ne_u32_e32 [[CMP_CMP:vcc]], 0, [[V_CMP]]
; SI: v_cndmask_b32_e64 [[RESULT:v[0-9]+]], 0, -1, [[CMP_CMP]]
; SI: buffer_store_dword [[RESULT]]
define void @sgpr_if_else_valu_cmp_phi_br(i32 addrspace(1)* %out, i32 addrspace(1)* %a, i32 addrspace(1)* %b) {
entry:
%tid = call i32 @llvm.amdgcn.workitem.id.x() #0
%tmp1 = icmp eq i32 %tid, 0
br i1 %tmp1, label %if, label %else
if:
%gep.if = getelementptr i32, i32 addrspace(1)* %a, i32 %tid
%a.val = load i32, i32 addrspace(1)* %gep.if
%cmp.if = icmp eq i32 %a.val, 0
br label %endif
else:
%gep.else = getelementptr i32, i32 addrspace(1)* %b, i32 %tid
%b.val = load i32, i32 addrspace(1)* %gep.else
%cmp.else = icmp slt i32 %b.val, 0
br label %endif
endif:
%tmp4 = phi i1 [%cmp.if, %if], [%cmp.else, %else]
%ext = sext i1 %tmp4 to i32
store i32 %ext, i32 addrspace(1)* %out
ret void
}
declare i32 @llvm.amdgcn.workitem.id.x() #0
attributes #0 = { readnone }