[llvm] r274569 - DAGCombiner: Fold away vector extract of insert with the same index
Mikael Holmén via llvm-commits
llvm-commits at lists.llvm.org
Wed Jul 6 02:21:53 PDT 2016
Hi Matt and Nadav,
This commit seems to make the X86 backend crash on the attached input.
llc -march=x86-64 -mcpu=corei7 red.ll
[...]
=== autogen_SD13436
Initial selection DAG: BB#0 'autogen_SD13436:BB'
SelectionDAG has 14 nodes:
t0: ch = EntryToken
t2: i32,ch = CopyFromReg t0, Register:i32 %vreg1
t7: i32 = Constant<0>
t4: i1 = setcc t2, t2, setult:ch
t9: v1i1 = insert_vector_elt undef:v1i1, Constant:i1<-1>,
Constant:i64<0>
t10: v1i1 = select t4, undef:v1i1, t9
t11: i8 = extract_vector_elt t10, Constant:i64<0>
t13: ch = CopyToReg t0, Register:i8 %vreg0, t11
Combining: t13: ch = CopyToReg t0, Register:i8 %vreg0, t11
Combining: t12: i8 = Register %vreg0
Combining: t11: i8 = extract_vector_elt t10, Constant:i64<0>
Combining: t10: v1i1 = select t4, undef:v1i1, t9
... into: t9: v1i1 = insert_vector_elt undef:v1i1, Constant:i1<-1>,
Constant:i64<0>
Combining: t11: i8 = extract_vector_elt t9, Constant:i64<0>
... into: t6: i1 = Constant<-1>
llc: ../lib/CodeGen/SelectionDAG/SelectionDAG.cpp:6357: void
llvm::SelectionDAG::ReplaceAllUsesWith(llvm::SDNode *, llvm::SDNode *):
Assertion `(!From->hasAnyUseOfValue(i) || From->getValueType(i) ==
To->getValueType(i)) && "Cannot use this version of
ReplaceAllUsesWith!"' failed.
#0 0x000000000254acbf llvm::sys::PrintStackTrace(llvm::raw_ostream&)
/data/repo/llvm-patch/build-all-Debug/../lib/Support/Unix/Signals.inc:402:5
#1 0x000000000254b1c9 PrintStackTraceSignalHandler(void*)
/data/repo/llvm-patch/build-all-Debug/../lib/Support/Unix/Signals.inc:470:1
#2 0x0000000002549823 llvm::sys::RunSignalHandlers()
/data/repo/llvm-patch/build-all-Debug/../lib/Support/Signals.cpp:45:5
#3 0x000000000254b7fe SignalHandler(int)
/data/repo/llvm-patch/build-all-Debug/../lib/Support/Unix/Signals.inc:256:1
#4 0x00007f3e718d0330 __restore_rt
(/lib/x86_64-linux-gnu/libpthread.so.0+0x10330)
#5 0x00007f3e704c3c37 gsignal
/build/eglibc-oGUzwX/eglibc-2.19/signal/../nptl/sysdeps/unix/sysv/linux/raise.c:56:0
#6 0x00007f3e704c7028 abort
/build/eglibc-oGUzwX/eglibc-2.19/stdlib/abort.c:91:0
#7 0x00007f3e704bcbf6 __assert_fail_base
/build/eglibc-oGUzwX/eglibc-2.19/assert/assert.c:92:0
#8 0x00007f3e704bcca2 (/lib/x86_64-linux-gnu/libc.so.6+0x2fca2)
#9 0x000000000234de74
llvm::SelectionDAG::ReplaceAllUsesWith(llvm::SDNode*, llvm::SDNode*)
/data/repo/llvm-patch/build-all-Debug/../lib/CodeGen/SelectionDAG/SelectionDAG.cpp:6355:5
#10 0x00000000021e51cb (anonymous
namespace)::DAGCombiner::Run(llvm::CombineLevel)
/data/repo/llvm-patch/build-all-Debug/../lib/CodeGen/SelectionDAG/DAGCombiner.cpp:1337:7
#11 0x00000000021e4a92 llvm::SelectionDAG::Combine(llvm::CombineLevel,
llvm::AAResults&, llvm::CodeGenOpt::Level)
/data/repo/llvm-patch/build-all-Debug/../lib/CodeGen/SelectionDAG/DAGCombiner.cpp:15038:3
#12 0x000000000239e004 llvm::SelectionDAGISel::CodeGenAndEmitDAG()
/data/repo/llvm-patch/build-all-Debug/../lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp:755:5
#13 0x000000000239dbee
llvm::SelectionDAGISel::SelectBasicBlock(llvm::ilist_iterator<llvm::Instruction
const>, llvm::ilist_iterator<llvm::Instruction const>, bool&)
/data/repo/llvm-patch/build-all-Debug/../lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp:680:1
#14 0x000000000239da33
llvm::SelectionDAGISel::SelectAllBasicBlocks(llvm::Function const&)
/data/repo/llvm-patch/build-all-Debug/../lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp:1485:5
#15 0x000000000239b81b
llvm::SelectionDAGISel::runOnMachineFunction(llvm::MachineFunction&)
/data/repo/llvm-patch/build-all-Debug/../lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp:505:36
#16 0x00000000015ae72b (anonymous
namespace)::X86DAGToDAGISel::runOnMachineFunction(llvm::MachineFunction&) /data/repo/llvm-patch/build-all-Debug/../lib/Target/X86/X86ISelDAGToDAG.cpp:175:25
#17 0x0000000001c0e27b
llvm::MachineFunctionPass::runOnFunction(llvm::Function&)
/data/repo/llvm-patch/build-all-Debug/../lib/CodeGen/MachineFunctionPass.cpp:60:8
#18 0x0000000001f9af8d
llvm::FPPassManager::runOnFunction(llvm::Function&)
/data/repo/llvm-patch/build-all-Debug/../lib/IR/LegacyPassManager.cpp:1526:23
#19 0x0000000001f9b2c5 llvm::FPPassManager::runOnModule(llvm::Module&)
/data/repo/llvm-patch/build-all-Debug/../lib/IR/LegacyPassManager.cpp:1547:16
#20 0x0000000001f9baae (anonymous
namespace)::MPPassManager::runOnModule(llvm::Module&)
/data/repo/llvm-patch/build-all-Debug/../lib/IR/LegacyPassManager.cpp:1603:23
#21 0x0000000001f9b5ab llvm::legacy::PassManagerImpl::run(llvm::Module&)
/data/repo/llvm-patch/build-all-Debug/../lib/IR/LegacyPassManager.cpp:1706:16
#22 0x0000000001f9bff1 llvm::legacy::PassManager::run(llvm::Module&)
/data/repo/llvm-patch/build-all-Debug/../lib/IR/LegacyPassManager.cpp:1737:3
#23 0x000000000086ca58 compileModule(char**, llvm::LLVMContext&)
/data/repo/llvm-patch/build-all-Debug/../tools/llc/llc.cpp:483:42
#24 0x000000000086af31 main
/data/repo/llvm-patch/build-all-Debug/../tools/llc/llc.cpp:260:13
#25 0x00007f3e704aef45 __libc_start_main
/build/eglibc-oGUzwX/eglibc-2.19/csu/libc-start.c:321:0
#26 0x000000000086aae4 _start (build-all-Debug/bin/llc+0x86aae4)
Stack dump:
0. Program arguments: build-all-Debug/bin/llc -march=x86-64
-mcpu=corei7 red.ll -debug
1. Running pass 'Function Pass Manager' on module 'red.ll'.
2. Running pass 'X86 DAG->DAG Instruction Selection' on function
'@autogen_SD13436'
In the debugger:
#4 0x000000000234de74 in llvm::SelectionDAG::ReplaceAllUsesWith
(this=0x3f2e490, From=0x3f87280, To=0x3f87050) at
../lib/CodeGen/SelectionDAG/SelectionDAG.cpp:6355
6355 assert((!From->hasAnyUseOfValue(i) ||
(gdb) l
6352 void SelectionDAG::ReplaceAllUsesWith(SDNode *From, SDNode *To) {
6353 #ifndef NDEBUG
6354 for (unsigned i = 0, e = From->getNumValues(); i != e; ++i)
6355 assert((!From->hasAnyUseOfValue(i) ||
6356 From->getValueType(i) == To->getValueType(i)) &&
6357 "Cannot use this version of ReplaceAllUsesWith!");
6358 #endif
6359
(gdb) p i
$1 = 0
(gdb) p From->hasAnyUseOfValue(i)
$2 = true
(gdb) p From->getValueType(i)
$3 = {V = {SimpleTy = llvm::MVT::i8}, LLVMTy = 0x0}
(gdb) p To->getValueType(i)
$4 = {V = {SimpleTy = llvm::MVT::i1}, LLVMTy = 0x0}
(gdb) call From->dump()
t11: i8 = extract_vector_elt t9, Constant:i64<0>
(gdb) call To->dump()
t6: i1 = Constant<-1>
The input file was generated with llvm-stress and then bugpoint and
manually reduced.
Regards,
Mikael
On 07/05/2016 08:25 PM, Matt Arsenault via llvm-commits wrote:
> Author: arsenm
> Date: Tue Jul 5 13:25:02 2016
> New Revision: 274569
>
> URL: http://llvm.org/viewvc/llvm-project?rev=274569&view=rev
> Log:
> DAGCombiner: Fold away vector extract of insert with the same index
>
> This only really matters when the index is non-constant since the
> constant case already gets taken care of by other combines.
>
> Added:
> llvm/trunk/test/CodeGen/AMDGPU/vector-extract-insert.ll
> Modified:
> llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
>
> Modified: llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp?rev=274569&r1=274568&r2=274569&view=diff
> ==============================================================================
> --- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original)
> +++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Tue Jul 5 13:25:02 2016
> @@ -12397,6 +12397,14 @@ SDValue DAGCombiner::visitEXTRACT_VECTOR
> return DAG.getNode(ISD::TRUNCATE, SDLoc(N), NVT, BCSrc);
> }
>
> + // extract_vector_elt (insert_vector_elt vec, val, idx), idx) -> val
> + //
> + // This only really matters if the index is non-constant since other combines
> + // on the constant elements already work.
> + if (InVec.getOpcode() == ISD::INSERT_VECTOR_ELT &&
> + EltNo == InVec.getOperand(2))
> + return InVec.getOperand(1);
> +
> // Transform: (EXTRACT_VECTOR_ELT( VECTOR_SHUFFLE )) -> EXTRACT_VECTOR_ELT.
> // We only perform this optimization before the op legalization phase because
> // we may introduce new vector instructions which are not backed by TD
>
> Added: llvm/trunk/test/CodeGen/AMDGPU/vector-extract-insert.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AMDGPU/vector-extract-insert.ll?rev=274569&view=auto
> ==============================================================================
> --- llvm/trunk/test/CodeGen/AMDGPU/vector-extract-insert.ll (added)
> +++ llvm/trunk/test/CodeGen/AMDGPU/vector-extract-insert.ll Tue Jul 5 13:25:02 2016
> @@ -0,0 +1,66 @@
> +; RUN: llc -march=amdgcn -verify-machineinstrs < %s | FileCheck -check-prefix=GCN %s
> +
> +; Test that when extracting the same unknown vector index from an
> +; insertelement the dynamic indexing is folded away.
> +
> +declare i32 @llvm.amdgcn.workitem.id.x() #0
> +
> +; No dynamic indexing required
> +; GCN-LABEL: {{^}}extract_insert_same_dynelt_v4i32:
> +; GCN: s_load_dword [[VAL:s[0-9]+]], s{{\[[0-9]+:[0-9]+\]}}, 0xd{{$}}
> +; GCN-NOT buffer_load_dword
> +; GCN-NOT: [[VAL]]
> +; GCN: v_mov_b32_e32 [[VVAL:v[0-9]+]], [[VAL]]
> +; GCN-NOT: [[VVAL]]
> +; GCN: buffer_store_dword [[VVAL]]
> +define void @extract_insert_same_dynelt_v4i32(i32 addrspace(1)* %out, <4 x i32> addrspace(1)* %in, i32 %val, i32 %idx) #1 {
> + %id = call i32 @llvm.amdgcn.workitem.id.x()
> + %id.ext = sext i32 %id to i64
> + %gep.in = getelementptr inbounds <4 x i32>, <4 x i32> addrspace(1)* %in, i64 %id.ext
> + %gep.out = getelementptr inbounds i32, i32 addrspace(1)* %out, i64 %id.ext
> + %vec = load <4 x i32>, <4 x i32> addrspace(1)* %gep.in
> + %insert = insertelement <4 x i32> %vec, i32 %val, i32 %idx
> + %extract = extractelement <4 x i32> %insert, i32 %idx
> + store i32 %extract, i32 addrspace(1)* %gep.out
> + ret void
> +}
> +
> +; GCN-LABEL: {{^}}extract_insert_different_dynelt_v4i32:
> +; GCN: buffer_load_dwordx4
> +; GCN: v_movreld_b32
> +; GCN: v_movrels_b32
> +; GCN: buffer_store_dword v
> +define void @extract_insert_different_dynelt_v4i32(i32 addrspace(1)* %out, <4 x i32> addrspace(1)* %in, i32 %val, i32 %idx0, i32 %idx1) #1 {
> + %id = call i32 @llvm.amdgcn.workitem.id.x()
> + %id.ext = sext i32 %id to i64
> + %gep.in = getelementptr inbounds <4 x i32>, <4 x i32> addrspace(1)* %in, i64 %id.ext
> + %gep.out = getelementptr inbounds i32, i32 addrspace(1)* %out, i64 %id.ext
> + %vec = load <4 x i32>, <4 x i32> addrspace(1)* %gep.in
> + %insert = insertelement <4 x i32> %vec, i32 %val, i32 %idx0
> + %extract = extractelement <4 x i32> %insert, i32 %idx1
> + store i32 %extract, i32 addrspace(1)* %gep.out
> + ret void
> +}
> +
> +; GCN-LABEL: {{^}}extract_insert_same_elt2_v4i32:
> +; GCN: s_load_dword [[VAL:s[0-9]+]], s{{\[[0-9]+:[0-9]+\]}}, 0xd{{$}}
> +; GCN-NOT buffer_load_dword
> +; GCN-NOT: [[VAL]]
> +; GCN: v_mov_b32_e32 [[VVAL:v[0-9]+]], [[VAL]]
> +; GCN-NOT: [[VVAL]]
> +; GCN: buffer_store_dword [[VVAL]]
> +define void @extract_insert_same_elt2_v4i32(i32 addrspace(1)* %out, <4 x i32> addrspace(1)* %in, i32 %val, i32 %idx) #1 {
> + %id = call i32 @llvm.amdgcn.workitem.id.x()
> + %id.ext = sext i32 %id to i64
> + %gep.in = getelementptr inbounds <4 x i32>, <4 x i32> addrspace(1)* %in, i64 %id.ext
> + %gep.out = getelementptr inbounds i32, i32 addrspace(1)* %out, i64 %id.ext
> + %vec = load <4 x i32>, <4 x i32> addrspace(1)* %gep.in
> + %insert = insertelement <4 x i32> %vec, i32 %val, i32 %idx
> + %extract = extractelement <4 x i32> %insert, i32 %idx
> + store i32 %extract, i32 addrspace(1)* %gep.out
> + ret void
> +}
> +
> +
> +attributes #0 = { nounwind readnone }
> +attributes #1 = { nounwind }
> \ No newline at end of file
>
>
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-------------- next part --------------
; ModuleID = 'bugpoint-reduced-simplified.bc'
source_filename = "red.ll"
target triple = "x86_64-unknown-linux-gnu"
define void @autogen_SD13436(i32) {
BB:
%Cmp57 = icmp ult i32 %0, %0
br label %CF245
CF245: ; preds = %CF274, %BB
%I115 = insertelement <1 x i1> undef, i1 true, i32 0
%Sl130 = select i1 %Cmp57, <1 x i1> undef, <1 x i1> %I115
%I135 = insertelement <1 x i1> %Sl130, i1 undef, i32 0
br label %CF274
CF274: ; preds = %CF245
%Shuff153 = shufflevector <1 x i1> undef, <1 x i1> %Sl130, <1 x i32> undef
%Cmp157 = fcmp olt double 0xA5677A86B265BD04, 0xA5677A86B265BD04
br i1 %Cmp157, label %CF245, label %CF235
CF235: ; preds = %CF235, %CF274
br label %CF235
}
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