[ConstantFold] llvm crashes when folding a GEP with vector index

[llvmbot]

Bugzilla Link	34880
Resolution	FIXED
Resolved on	Dec 05, 2017 14:41
Version	trunk
OS	Linux
Blocks	#33840
Reporter	LLVM Bugzilla Contributor
CC	@majnemer,@tstellar
Fixed by commit(s)	r316824 r318096

Extended Description

opt -instsimplify -S crashes with following IRs

target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"

@​block = global [64 x [8192 x i8]] zeroinitializer, align 1

define <2 x i8*> @​foo() {
%1 = getelementptr inbounds [64 x [8192 x i8]], [64 x [8192 x i8]]* @​block, i64 0, <2 x i64> <i64 0, i64 1>, i64 8192
ret <2 x i8*> %1
}

The llvm output is

opt: /local/mnt/workspace/tools/clean/llvm/include/llvm/Support/Casting.h:255: typename cast_retty<X, Y >::ret_type llvm::cast(Y ) [X = llvm::IntegerType, Y = const llvm::Type]: Assertion `isa(Val) && "cast() argument of incompatible type!"' failed.
#​0 0x0000000001d01a94 PrintStackTraceSignalHandler(void) (/local/mnt/workspace/tools/clean/install/bin/opt+0x1d01a94)
#​1 0x0000000001d01db6 SignalHandler(int) (/local/mnt/workspace/tools/clean/install/bin/opt+0x1d01db6)
#​2 0x00007fe5538f9330 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x10330)
#​3 0x00007fe553556c37 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x36c37)
#​4 0x00007fe55355a028 abort (/lib/x86_64-linux-gnu/libc.so.6+0x3a028)
#​5 0x00007fe55354fbf6 (/lib/x86_64-linux-gnu/libc.so.6+0x2fbf6)
#​6 0x00007fe55354fca2 (/lib/x86_64-linux-gnu/libc.so.6+0x2fca2)
#​7 0x000000000170df60 llvm::ConstantFoldGetElementPtr(llvm::Type, llvm::Constant*, bool, llvm::Optional, llvm::ArrayRefllvm::Value*) (/local/mnt/workspace/tools/clean/install/bin/opt+0x170df60)
#​8 0x0000000001726580 llvm::ConstantExpr::getGetElementPtr(llvm::Type*, llvm::Constant*, llvm::ArrayRefllvm::Value*, bool, llvm::Optional, llvm::Type*) (/local/mnt/workspace/tools/clean/install/bin/opt+0x1726580)
#​9 0x000000000129287a llvm::SimplifyGEPInst(llvm::Type*, llvm::ArrayRefllvm::Value*, llvm::SimplifyQuery const&) (/local/mnt/workspace/tools/clean/install/bin/opt+0x129287a)
#​10 0x00000000012956c8 llvm::SimplifyInstruction(llvm::Instruction*, llvm::SimplifyQuery const&, llvm::OptimizationRemarkEmitter*) (/local/mnt/workspace/tools/clean/install/bin/opt+0x12956c8)
#​11 0x0000000001dd6e2e runImpl(llvm::Function&, llvm::SimplifyQuery const&, llvm::OptimizationRemarkEmitter*) (/local/mnt/workspace/tools/clean/install/bin/opt+0x1dd6e2e)
#​12 0x0000000001dd75cc (anonymous namespace)::InstSimplifier::runOnFunction(llvm::Function&) (/local/mnt/workspace/tools/clean/install/bin/opt+0x1dd75cc)
#​13 0x00000000017d44ef llvm::FPPassManager::runOnFunction(llvm::Function&) (/local/mnt/workspace/tools/clean/install/bin/opt+0x17d44ef)
#​14 0x00000000017d4743 llvm::FPPassManager::runOnModule(llvm::Module&) (/local/mnt/workspace/tools/clean/install/bin/opt+0x17d4743)
#​15 0x00000000017d4c45 llvm::legacy::PassManagerImpl::run(llvm::Module&) (/local/mnt/workspace/tools/clean/install/bin/opt+0x17d4c45)
#​16 0x0000000000704678 main (/local/mnt/workspace/tools/clean/install/bin/opt+0x704678)
#​17 0x00007fe553541f45 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21f45)
#​18 0x00000000006f60ed _start /local/mnt/workspace/sysroots/.build/x86_64-dcg-linux-gnu/build/src/glibc/csu/../sysdeps/x86_64/elf/start.S:116:0
Stack dump:
0. Program arguments: /local/mnt/workspace/tools/clean/install/bin/opt -instsimplify -S

1. Running pass 'Function Pass Manager' on module ''.
2. Running pass 'Remove redundant instructions' on function '@foo'
   Aborted (core dumped)

It is reduced from a real application.

[llvmbot]

Patch to fix: https://reviews.llvm.org/D38677

[llvmbot]

Fixed in r316824.