diff --git a/llvm/lib/Target/X86/X86ISelLowering.h b/llvm/lib/Target/X86/X86ISelLowering.h --- a/llvm/lib/Target/X86/X86ISelLowering.h +++ b/llvm/lib/Target/X86/X86ISelLowering.h @@ -855,7 +855,7 @@ /// Returns true of the given offset can be /// fit into displacement field of the instruction. bool isOffsetSuitableForCodeModel(int64_t Offset, CodeModel::Model M, - bool hasSymbolicDisplacement = true); + bool hasSymbolicDisplacement); /// Determines whether the callee is required to pop its /// own arguments. Callee pop is necessary to support tail calls. diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp --- a/llvm/lib/Target/X86/X86ISelLowering.cpp +++ b/llvm/lib/Target/X86/X86ISelLowering.cpp @@ -19102,9 +19102,12 @@ if (GV) { // Create a target global address if this is a global. If possible, fold the // offset into the global address reference. Otherwise, ADD it on later. + // Suppress the folding if Offset is negative: movl foo-1, %eax is not + // allowed because if the address of foo is 0, the ELF R_X86_64_32 + // relocation will compute to a negative value, which is invalid. int64_t GlobalOffset = 0; - if (OpFlags == X86II::MO_NO_FLAG && - X86::isOffsetSuitableForCodeModel(Offset, M)) { + if (OpFlags == X86II::MO_NO_FLAG && Offset >= 0 && + X86::isOffsetSuitableForCodeModel(Offset, M, true)) { std::swap(GlobalOffset, Offset); } Result = DAG.getTargetGlobalAddress(GV, dl, PtrVT, GlobalOffset, OpFlags); diff --git a/llvm/test/CodeGen/X86/fold-add.ll b/llvm/test/CodeGen/X86/fold-add.ll --- a/llvm/test/CodeGen/X86/fold-add.ll +++ b/llvm/test/CodeGen/X86/fold-add.ll @@ -54,10 +54,12 @@ ret i64 add (i64 ptrtoint (i32* @foo to i64), i64 1701208431) } +;; Test we don't emit movl foo-1, %eax. ELF R_X86_64_32 does not allow +;; a negative value. define dso_local i64 @neg_1() #0 { ; CHECK-LABEL: neg_1: ; CHECK: # %bb.0: -; STATIC-NEXT: movl $foo-1, %eax +; STATIC-NEXT: leaq foo-1(%rip), %rax ; PIC-NEXT: leaq foo-1(%rip), %rax ; MSTATIC-NEXT: movabsq $foo, %rax ; MSTATIC-NEXT: decq %rax @@ -68,10 +70,12 @@ ret i64 add (i64 ptrtoint (i32* @foo to i64), i64 -1) } +;; Test we don't emit movl foo-2147483648, %eax. ELF R_X86_64_32 does not allow +;; a negative value. define dso_local i64 @neg_0x80000000() #0 { ; CHECK-LABEL: neg_0x80000000: ; CHECK: # %bb.0: -; STATIC-NEXT: movl $foo-2147483648, %eax +; STATIC-NEXT: leaq foo-2147483648(%rip), %rax ; PIC-NEXT: leaq foo-2147483648(%rip), %rax ; MSTATIC-NEXT: movabsq $foo, %rax ; MSTATIC-NEXT: addq $-2147483648, %rax