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to not guess at a symbol name in some cases. The problem is that in object files assembled starting at address 0, when trying to symbolicate something that starts like this: % cat x.s _t1: vpshufd $0x0, %xmm1, %xmm0 the symbolic disassembly can end up like this: % otool -tV x.o x.o: (__TEXT,__text) section _t1: 0000000000000000 vpshufd $_t1, %xmm1, %xmm0 Which is in this case produced incorrect symbolication. But it is useful in some cases to use the SymbolLookUp() call back to guess at some immediate values. For example one like this that does not have an external relocation entry: % cat y.s _t1: movl $_d1, %eax .data _d1: .long 0 % clang -c -arch i386 y.s % otool -tV y.o y.o: (__TEXT,__text) section _t1: 0000000000000000 movl $_d1, %eax % otool -rv y.o y.o: Relocation information (__TEXT,__text) 1 entries address pcrel length extern type scattered symbolnum/value 00000001 False long False VANILLA False 2 (__DATA,__data) So the change is based on it is not likely that an immediate Value coming from an instruction field of a width of 1 byte, other than branches and items with relocation, are not likely symbol addresses. With the change the first case above simply becomes: % otool -tV x.o x.o: (__TEXT,__text) section _t1: 0000000000000000 vpshufd $0x0, %xmm1, %xmm0 and the second case continues to work as expected. rdar://14863405 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199698 91177308-0d34-0410-b5e6-96231b3b80d8
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