spill-scavenge-offset.ll 4.7 KB
; RUN: llc -march=amdgcn -mcpu=verde -enable-misched=0 -post-RA-scheduler=0 -amdgpu-spill-sgpr-to-vgpr=0 < %s | FileCheck -check-prefixes=CHECK,GFX6 %s
; RUN: llc -regalloc=basic -march=amdgcn -mcpu=tonga -enable-misched=0 -post-RA-scheduler=0 -amdgpu-spill-sgpr-to-vgpr=0 < %s | FileCheck -check-prefixes=CHECK,GFX7 %s
;
; There is something about Tonga that causes this test to spend a lot of time
; in the default register allocator.


; When the offset of VGPR spills into scratch space gets too large, an additional SGPR
; is used to calculate the scratch load/store address. Make sure that this
; mechanism works even when many spills happen.

; Just test that it compiles successfully.
; CHECK-LABEL: test
define amdgpu_kernel void @test(<1280 x i32> addrspace(1)* %out, <1280 x i32> addrspace(1)* %in) {
entry:
  %lo = call i32 @llvm.amdgcn.mbcnt.lo(i32 -1, i32 0)
  %tid = call i32 @llvm.amdgcn.mbcnt.hi(i32 -1, i32 %lo)

  %aptr = getelementptr <1280 x i32>, <1280 x i32> addrspace(1)* %in, i32 %tid
  %a = load <1280 x i32>, <1280 x i32> addrspace(1)* %aptr

; mark most VGPR registers as used to increase register pressure
  call void asm sideeffect "", "~{v4},~{v8},~{v12},~{v16},~{v20},~{v24},~{v28},~{v32}" ()
  call void asm sideeffect "", "~{v36},~{v40},~{v44},~{v48},~{v52},~{v56},~{v60},~{v64}" ()
  call void asm sideeffect "", "~{v68},~{v72},~{v76},~{v80},~{v84},~{v88},~{v92},~{v96}" ()
  call void asm sideeffect "", "~{v100},~{v104},~{v108},~{v112},~{v116},~{v120},~{v124},~{v128}" ()
  call void asm sideeffect "", "~{v132},~{v136},~{v140},~{v144},~{v148},~{v152},~{v156},~{v160}" ()
  call void asm sideeffect "", "~{v164},~{v168},~{v172},~{v176},~{v180},~{v184},~{v188},~{v192}" ()
  call void asm sideeffect "", "~{v196},~{v200},~{v204},~{v208},~{v212},~{v216},~{v220},~{v224}" ()

  %outptr = getelementptr <1280 x i32>, <1280 x i32> addrspace(1)* %out, i32 %tid
  store <1280 x i32> %a, <1280 x i32> addrspace(1)* %outptr

  ret void
}

; CHECK-LABEL: test_limited_sgpr
; GFX6: s_add_u32 s32, s32, 0x[[OFFSET:[0-9]+]]
; GFX6-NEXT: buffer_load_dword v{{[0-9]+}}, off, s[{{[0-9:]+}}], s32
; GFX6-NEXT: s_sub_u32 s32, s32, 0x[[OFFSET:[0-9]+]]
; GFX6: NumSgprs: 48
; GFX6: ScratchSize: 8624
define amdgpu_kernel void @test_limited_sgpr(<64 x i32> addrspace(1)* %out, <64 x i32> addrspace(1)* %in) #0 {
entry:
  %lo = call i32 @llvm.amdgcn.mbcnt.lo(i32 -1, i32 0)
  %tid = call i32 @llvm.amdgcn.mbcnt.hi(i32 -1, i32 %lo)

; allocate enough scratch to go beyond 2^12 addressing
  %scratch = alloca <1280 x i32>, align 8, addrspace(5)

; load VGPR data
  %aptr = getelementptr <64 x i32>, <64 x i32> addrspace(1)* %in, i32 %tid
  %a = load <64 x i32>, <64 x i32> addrspace(1)* %aptr

; make sure scratch is used
  %x = extractelement <64 x i32> %a, i32 0
  %sptr0 = getelementptr <1280 x i32>, <1280 x i32> addrspace(5)* %scratch, i32 %x, i32 0
  store i32 1, i32 addrspace(5)* %sptr0

; fill up SGPRs
  %sgpr0 = call <8 x i32> asm sideeffect "; def $0", "=s" ()
  %sgpr1 = call <8 x i32> asm sideeffect "; def $0", "=s" ()
  %sgpr2 = call <8 x i32> asm sideeffect "; def $0", "=s" ()
  %sgpr3 = call <8 x i32> asm sideeffect "; def $0", "=s" ()
  %sgpr4 = call <4 x i32> asm sideeffect "; def $0", "=s" ()
  %sgpr5 = call <2 x i32> asm sideeffect "; def $0", "=s" ()
  %sgpr6 = call <2 x i32> asm sideeffect "; def $0", "=s" ()
  %sgpr7 = call i32 asm sideeffect "; def $0", "=s" ()

  %cmp = icmp eq i32 %x, 0
  br i1 %cmp, label %bb0, label %ret

bb0:
; create SGPR pressure
  call void asm sideeffect "; use $0,$1,$2,$3,$4,$5,$6", "s,s,s,s,s,s,s,s"(<8 x i32> %sgpr0, <8 x i32> %sgpr1, <8 x i32> %sgpr2, <8 x i32> %sgpr3, <4 x i32> %sgpr4, <2 x i32> %sgpr5, <2 x i32> %sgpr6, i32 %sgpr7)

; mark most VGPR registers as used to increase register pressure
  call void asm sideeffect "", "~{v4},~{v8},~{v12},~{v16},~{v20},~{v24},~{v28},~{v32}" ()
  call void asm sideeffect "", "~{v36},~{v40},~{v44},~{v48},~{v52},~{v56},~{v60},~{v64}" ()
  call void asm sideeffect "", "~{v68},~{v72},~{v76},~{v80},~{v84},~{v88},~{v92},~{v96}" ()
  call void asm sideeffect "", "~{v100},~{v104},~{v108},~{v112},~{v116},~{v120},~{v124},~{v128}" ()
  call void asm sideeffect "", "~{v132},~{v136},~{v140},~{v144},~{v148},~{v152},~{v156},~{v160}" ()
  call void asm sideeffect "", "~{v164},~{v168},~{v172},~{v176},~{v180},~{v184},~{v188},~{v192}" ()
  call void asm sideeffect "", "~{v196},~{v200},~{v204},~{v208},~{v212},~{v216},~{v220},~{v224}" ()
  br label %ret

ret:
  %outptr = getelementptr <64 x i32>, <64 x i32> addrspace(1)* %out, i32 %tid
  store <64 x i32> %a, <64 x i32> addrspace(1)* %outptr

  ret void
}

declare i32 @llvm.amdgcn.mbcnt.lo(i32, i32) #1
declare i32 @llvm.amdgcn.mbcnt.hi(i32, i32) #1

attributes #0 = { "amdgpu-waves-per-eu"="10,10" }
attributes #1 = { nounwind readnone }