llvm/test/CodeGen/AMDGPU/llvm.amdgcn.buffer.load.ll
Nicolai Haehnle 682fc3e780 AMDGPU: Fix MUBUF offset bugs affecting llvm.amdgcn.buffer.* intrinsics
Summary:
This fixes two related bugs. First, the generic optimization passes
unfortunately generate negative constant offsets but the hardware treats
SOffset as an unsigned value.

Second, there is a hardware bug on SI and CI, where address clamping in MUBUF
instructions does not work correctly when SOffset is larger than the buffer
size. This patch works around this bug by never using SOffset.

An alternative workaround would be to do the clamping manually when SOffset
is too large, but generating the required code sequence during instruction
selection would be rather involved, and in any case the resulting code would
probably be worse.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=96360

Reviewers: arsenm, tstellarAMD

Subscribers: arsenm, llvm-commits, kzhuravl

Differential Revision: http://reviews.llvm.org/D21326

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@272761 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-15 07:13:05 +00:00

120 lines
4.9 KiB
LLVM

;RUN: llc < %s -march=amdgcn -mcpu=verde -verify-machineinstrs | FileCheck %s -check-prefix=CHECK -check-prefix=SICI
;RUN: llc < %s -march=amdgcn -mcpu=tonga -verify-machineinstrs | FileCheck %s -check-prefix=CHECK -check-prefix=VI
;CHECK-LABEL: {{^}}buffer_load:
;CHECK: buffer_load_dwordx4 v[0:3], off, s[0:3], 0
;CHECK: buffer_load_dwordx4 v[4:7], off, s[0:3], 0 glc
;CHECK: buffer_load_dwordx4 v[8:11], off, s[0:3], 0 slc
;CHECK: s_waitcnt
define amdgpu_ps {<4 x float>, <4 x float>, <4 x float>} @buffer_load(<4 x i32> inreg) {
main_body:
%data = call <4 x float> @llvm.amdgcn.buffer.load.v4f32(<4 x i32> %0, i32 0, i32 0, i1 0, i1 0)
%data_glc = call <4 x float> @llvm.amdgcn.buffer.load.v4f32(<4 x i32> %0, i32 0, i32 0, i1 1, i1 0)
%data_slc = call <4 x float> @llvm.amdgcn.buffer.load.v4f32(<4 x i32> %0, i32 0, i32 0, i1 0, i1 1)
%r0 = insertvalue {<4 x float>, <4 x float>, <4 x float>} undef, <4 x float> %data, 0
%r1 = insertvalue {<4 x float>, <4 x float>, <4 x float>} %r0, <4 x float> %data_glc, 1
%r2 = insertvalue {<4 x float>, <4 x float>, <4 x float>} %r1, <4 x float> %data_slc, 2
ret {<4 x float>, <4 x float>, <4 x float>} %r2
}
;CHECK-LABEL: {{^}}buffer_load_immoffs:
;CHECK: buffer_load_dwordx4 v[0:3], off, s[0:3], 0 offset:42
;CHECK: s_waitcnt
define amdgpu_ps <4 x float> @buffer_load_immoffs(<4 x i32> inreg) {
main_body:
%data = call <4 x float> @llvm.amdgcn.buffer.load.v4f32(<4 x i32> %0, i32 0, i32 42, i1 0, i1 0)
ret <4 x float> %data
}
;CHECK-LABEL: {{^}}buffer_load_immoffs_large:
;SICI: buffer_load_dwordx4 v[0:3], {{v[0-9]+}}, s[0:3], 0 offen
;VI: s_movk_i32 [[OFFSET:s[0-9]+]], 0x1fff
;VI: buffer_load_dwordx4 v[0:3], off, s[0:3], [[OFFSET]] offset:1
;CHECK: s_waitcnt
define amdgpu_ps <4 x float> @buffer_load_immoffs_large(<4 x i32> inreg) {
main_body:
%data = call <4 x float> @llvm.amdgcn.buffer.load.v4f32(<4 x i32> %0, i32 0, i32 8192, i1 0, i1 0)
ret <4 x float> %data
}
;CHECK-LABEL: {{^}}buffer_load_idx:
;CHECK: buffer_load_dwordx4 v[0:3], v0, s[0:3], 0 idxen
;CHECK: s_waitcnt
define amdgpu_ps <4 x float> @buffer_load_idx(<4 x i32> inreg, i32) {
main_body:
%data = call <4 x float> @llvm.amdgcn.buffer.load.v4f32(<4 x i32> %0, i32 %1, i32 0, i1 0, i1 0)
ret <4 x float> %data
}
;CHECK-LABEL: {{^}}buffer_load_ofs:
;CHECK: buffer_load_dwordx4 v[0:3], v0, s[0:3], 0 offen
;CHECK: s_waitcnt
define amdgpu_ps <4 x float> @buffer_load_ofs(<4 x i32> inreg, i32) {
main_body:
%data = call <4 x float> @llvm.amdgcn.buffer.load.v4f32(<4 x i32> %0, i32 0, i32 %1, i1 0, i1 0)
ret <4 x float> %data
}
;CHECK-LABEL: {{^}}buffer_load_ofs_imm:
;CHECK: buffer_load_dwordx4 v[0:3], v0, s[0:3], 0 offen offset:58
;CHECK: s_waitcnt
define amdgpu_ps <4 x float> @buffer_load_ofs_imm(<4 x i32> inreg, i32) {
main_body:
%ofs = add i32 %1, 58
%data = call <4 x float> @llvm.amdgcn.buffer.load.v4f32(<4 x i32> %0, i32 0, i32 %ofs, i1 0, i1 0)
ret <4 x float> %data
}
;CHECK-LABEL: {{^}}buffer_load_both:
;CHECK: buffer_load_dwordx4 v[0:3], v[0:1], s[0:3], 0 idxen offen
;CHECK: s_waitcnt
define amdgpu_ps <4 x float> @buffer_load_both(<4 x i32> inreg, i32, i32) {
main_body:
%data = call <4 x float> @llvm.amdgcn.buffer.load.v4f32(<4 x i32> %0, i32 %1, i32 %2, i1 0, i1 0)
ret <4 x float> %data
}
;CHECK-LABEL: {{^}}buffer_load_both_reversed:
;CHECK: v_mov_b32_e32 v2, v0
;CHECK: buffer_load_dwordx4 v[0:3], v[1:2], s[0:3], 0 idxen offen
;CHECK: s_waitcnt
define amdgpu_ps <4 x float> @buffer_load_both_reversed(<4 x i32> inreg, i32, i32) {
main_body:
%data = call <4 x float> @llvm.amdgcn.buffer.load.v4f32(<4 x i32> %0, i32 %2, i32 %1, i1 0, i1 0)
ret <4 x float> %data
}
;CHECK-LABEL: {{^}}buffer_load_x1:
;CHECK: buffer_load_dword v0, v[0:1], s[0:3], 0 idxen offen
;CHECK: s_waitcnt
define amdgpu_ps float @buffer_load_x1(<4 x i32> inreg %rsrc, i32 %idx, i32 %ofs) {
main_body:
%data = call float @llvm.amdgcn.buffer.load.f32(<4 x i32> %rsrc, i32 %idx, i32 %ofs, i1 0, i1 0)
ret float %data
}
;CHECK-LABEL: {{^}}buffer_load_x2:
;CHECK: buffer_load_dwordx2 v[0:1], v[0:1], s[0:3], 0 idxen offen
;CHECK: s_waitcnt
define amdgpu_ps <2 x float> @buffer_load_x2(<4 x i32> inreg %rsrc, i32 %idx, i32 %ofs) {
main_body:
%data = call <2 x float> @llvm.amdgcn.buffer.load.v2f32(<4 x i32> %rsrc, i32 %idx, i32 %ofs, i1 0, i1 0)
ret <2 x float> %data
}
;CHECK-LABEL: {{^}}buffer_load_negative_offset:
;CHECK: v_add_i32_e32 [[VOFS:v[0-9]+]], vcc, -16, v0
;CHECK: buffer_load_dwordx4 v[0:3], [[VOFS]], s[0:3], 0 offen
define amdgpu_ps <4 x float> @buffer_load_negative_offset(<4 x i32> inreg, i32 %ofs) {
main_body:
%ofs.1 = add i32 %ofs, -16
%data = call <4 x float> @llvm.amdgcn.buffer.load.v4f32(<4 x i32> %0, i32 0, i32 %ofs.1, i1 0, i1 0)
ret <4 x float> %data
}
declare float @llvm.amdgcn.buffer.load.f32(<4 x i32>, i32, i32, i1, i1) #0
declare <2 x float> @llvm.amdgcn.buffer.load.v2f32(<4 x i32>, i32, i32, i1, i1) #0
declare <4 x float> @llvm.amdgcn.buffer.load.v4f32(<4 x i32>, i32, i32, i1, i1) #0
attributes #0 = { nounwind readonly }