PR10998: It is not legal to sink an instruction past the terminator of a block; make sure we don't do that.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@140428 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/TwoAddressInstructionPass.cpp b/lib/CodeGen/TwoAddressInstructionPass.cpp
index dfd258d..d879378 100644
--- a/lib/CodeGen/TwoAddressInstructionPass.cpp
+++ b/lib/CodeGen/TwoAddressInstructionPass.cpp
@@ -177,6 +177,10 @@
bool TwoAddressInstructionPass::Sink3AddrInstruction(MachineBasicBlock *MBB,
MachineInstr *MI, unsigned SavedReg,
MachineBasicBlock::iterator OldPos) {
+ // FIXME: Shouldn't we be trying to do this before we three-addressify the
+ // instruction? After this transformation is done, we no longer need
+ // the instruction to be in three-address form.
+
// Check if it's safe to move this instruction.
bool SeenStore = true; // Be conservative.
if (!MI->isSafeToMove(TII, AA, SeenStore))
@@ -217,7 +221,11 @@
break;
}
- if (!KillMI || KillMI->getParent() != MBB || KillMI == MI)
+ // If we find the instruction that kills SavedReg, and it is in an
+ // appropriate location, we can try to sink the current instruction
+ // past it.
+ if (!KillMI || KillMI->getParent() != MBB || KillMI == MI ||
+ KillMI->getDesc().isTerminator())
return false;
// If any of the definitions are used by another instruction between the
diff --git a/test/CodeGen/X86/twoaddr-sink-terminator.ll b/test/CodeGen/X86/twoaddr-sink-terminator.ll
new file mode 100644
index 0000000..209d474
--- /dev/null
+++ b/test/CodeGen/X86/twoaddr-sink-terminator.ll
@@ -0,0 +1,43 @@
+; RUN: llc < %s -verify-coalescing
+; PR10998
+
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32-n8:16:32"
+target triple = "i386-unknown-freebsd8.2"
+
+define void @test(i32 %arg1) nounwind align 2 {
+bb11:
+ %tmp13 = and i32 %arg1, 7
+ %tmp14 = add i32 %tmp13, -5
+ switch i32 %tmp13, label %bb18 [
+ i32 0, label %bb21
+ i32 4, label %bb22
+ i32 3, label %bb21
+ i32 2, label %bb19
+ ]
+
+bb18:
+ %tmp202 = call i32 @f() nounwind
+ unreachable
+
+bb19:
+ %tmp20 = call i32 @f() nounwind
+ br label %bb24
+
+bb21:
+ %tmp203 = call i32 @f() nounwind
+ br label %bb24
+
+bb22:
+ %tmp23 = call i32 @f() nounwind
+ br label %bb24
+
+bb24:
+ %tmp15 = icmp ult i32 %tmp14, 2
+ %tmp55 = select i1 %tmp15, i32 45, i32 44
+ %tmp56 = call i32 @f2(i32 %tmp55)
+ unreachable
+}
+
+declare i32 @f()
+
+declare i32 @f2(i32)
