Fix pr33010, a 2 year old crashing regression

preames · preames · commit ca13910a6c9c · 2019-05-06T22:09:31.000Z
The problem was that we were creating a CMOV64rr <TargetFrameIndex>, <TargetFrameIndex>. The entire point of a TFI is that address code is not generated, so there's no way to legalize/lower this. Instead, simply prevent it's creation. Arguably, we shouldn't be using *Target*FrameIndices in StatepointLowering at all, but that's a much deeper change. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@360090 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -19008,6 +19008,10 @@ bool DAGCombiner::SimplifySelectOps(SDNode *TheSelect, SDValue LHS,
         // locations are not in the default address space.
         LLD->getPointerInfo().getAddrSpace() != 0 ||
         RLD->getPointerInfo().getAddrSpace() != 0 ||
+        // We can't produce a CMOV of a TargetFrameIndex since we won't
+        // generate the address generation required.
+        LLD->getBasePtr().getOpcode() == ISD::TargetFrameIndex ||
+        RLD->getBasePtr().getOpcode() == ISD::TargetFrameIndex ||
         !TLI.isOperationLegalOrCustom(TheSelect->getOpcode(),
                                       LLD->getBasePtr().getValueType()))
       return false;
diff --git a/test/CodeGen/X86/pr33010.ll b/test/CodeGen/X86/pr33010.ll
@@ -0,0 +1,45 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -mtriple=x86_64-linux-generic < %s | FileCheck %s
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+
+; We can't create a select of two TargetFrameIndices since the rest
+; of the backend doesn't know how to handle such a construct.
+define i32 addrspace(1)* @test(i32 addrspace(1)* %a, i32 addrspace(1)* %b, i1 %which) gc "statepoint-example" {
+; CHECK-LABEL: test:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    pushq %rbx
+; CHECK-NEXT:    .cfi_def_cfa_offset 16
+; CHECK-NEXT:    subq $16, %rsp
+; CHECK-NEXT:    .cfi_def_cfa_offset 32
+; CHECK-NEXT:    .cfi_offset %rbx, -16
+; CHECK-NEXT:    movl %edx, %ebx
+; CHECK-NEXT:    movq %rdi, (%rsp)
+; CHECK-NEXT:    movq %rsi, {{[0-9]+}}(%rsp)
+; CHECK-NEXT:    callq f
+; CHECK-NEXT:  .Ltmp0:
+; CHECK-NEXT:    testb $1, %bl
+; CHECK-NEXT:    je .LBB0_1
+; CHECK-NEXT:  # %bb.2: # %entry
+; CHECK-NEXT:    movq (%rsp), %rax
+; CHECK-NEXT:    jmp .LBB0_3
+; CHECK-NEXT:  .LBB0_1:
+; CHECK-NEXT:    movq {{[0-9]+}}(%rsp), %rax
+; CHECK-NEXT:  .LBB0_3: # %entry
+; CHECK-NEXT:    addq $16, %rsp
+; CHECK-NEXT:    .cfi_def_cfa_offset 16
+; CHECK-NEXT:    popq %rbx
+; CHECK-NEXT:    .cfi_def_cfa_offset 8
+; CHECK-NEXT:    retq
+entry:
+  %tok = tail call token (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* @f, i32 0, i32 0, i32 0, i32 0, i32 addrspace(1)* %a, i32 addrspace(1)* %b)
+  %a.r = tail call coldcc i8 addrspace(1)* @llvm.experimental.gc.relocate.p1i8(token %tok, i32 7, i32 7) ; (%a, %a)
+  %b.r = tail call coldcc i8 addrspace(1)* @llvm.experimental.gc.relocate.p1i8(token %tok, i32 8, i32 8) ; (%b, %b)
+  %cond.v = select i1 %which, i8 addrspace(1)* %a.r, i8 addrspace(1)* %b.r
+  %cond = bitcast i8 addrspace(1)* %cond.v to i32 addrspace(1)*
+  ret i32 addrspace(1)* %cond
+}
+
+declare void @f()
+declare token @llvm.experimental.gc.statepoint.p0f_isVoidf(i64, i32, void ()*, i32, i32, ...)
+declare i8 addrspace(1)* @llvm.experimental.gc.relocate.p1i8(token, i32, i32)
