Don't always apply kill flag in thumb2 ABS pseudo expansion.

The expansion for t2ABS was always setting the kill flag on the rsb instruction.
It should instead only be set on rsb if it was set on the original ABS instruction.

rdar://problem/20752113

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236272 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 5f593d6f986986cdba5a1ea2d02702643a6580d5..bdcf86cfed6369866f9ddd988ed93e71e71a85ae 100644 (file)
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -7501,6 +7501,7 @@ ARMTargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI,
 
     unsigned int ABSSrcReg = MI->getOperand(1).getReg();
     unsigned int ABSDstReg = MI->getOperand(0).getReg();
+    bool ABSSrcKIll = MI->getOperand(1).isKill();
     bool isThumb2 = Subtarget->isThumb2();
     MachineRegisterInfo &MRI = Fn->getRegInfo();
     // In Thumb mode S must not be specified if source register is the SP or
@@ -7534,7 +7535,7 @@ ARMTargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI,
     // by if-conversion pass
     BuildMI(*RSBBB, RSBBB->begin(), dl,
       TII->get(isThumb2 ? ARM::t2RSBri : ARM::RSBri), NewRsbDstReg)
-      .addReg(ABSSrcReg, RegState::Kill)
+      .addReg(ABSSrcReg, ABSSrcKIll ? RegState::Kill : 0)
       .addImm(0).addImm((unsigned)ARMCC::AL).addReg(0).addReg(0);
 
     // insert PHI in SinkBB,

diff --git a/test/CodeGen/ARM/t2abs-killflags.ll b/test/CodeGen/ARM/t2abs-killflags.ll
new file mode 100644 (file)
index 0000000..eed8f67
--- /dev/null
+++ b/test/CodeGen/ARM/t2abs-killflags.ll
@@ -0,0 +1,23 @@
+; RUN: llc %s -o - -verify-machineinstrs | FileCheck %s
+
+target datalayout = "e-m:o-p:32:32-f64:32:64-v64:32:64-v128:32:128-a:0:32-n32-S32"
+target triple = "thumbv7s-unknown-unknown"
+
+; Test that we don't crash the machine verifier when expanding t2ABS.
+; It was applying the kill flag to its source, even if the original t2ABS didn't
+; kill the operand prior to pseudo expansion.
+
+; Function Attrs: noreturn
+declare void @foo(i32, i32) #0
+
+; CHECK-LABEL: @test
+; CHECK: rsbmi
+define void @test(i32 %arg) {
+  %cmp58 = icmp slt i32 %arg, 0
+  %sub62 = sub nsw i32 0, %arg
+  %l.1 = select i1 %cmp58, i32 %sub62, i32 %arg
+  call void @foo(i32 %l.1, i32 %arg) #0
+  unreachable
+}
+
+attributes #0 = { noreturn }