[llvm] r373738 - ARM-Darwin: keep the frame register reserved even if not updated.

[Tim Northover via llvm-commits]

Author: tnorthover
Date: Fri Oct  4 05:29:32 2019
New Revision: 373738

URL: http://llvm.org/viewvc/llvm-project?rev=373738&view=rev
Log:
ARM-Darwin: keep the frame register reserved even if not updated.

Darwin platforms need the frame register to always point at a valid record even
if it's not updated in a leaf function. Backtraces are more important than one
extra GPR.

Added:
    llvm/trunk/test/CodeGen/ARM/r7-fixed-darwin.ll
Modified:
    llvm/trunk/lib/Target/ARM/ARMBaseRegisterInfo.cpp
    llvm/trunk/test/CodeGen/Thumb/long.ll
    llvm/trunk/test/CodeGen/Thumb2/2010-03-15-AsmCCClobber.ll

Modified: llvm/trunk/lib/Target/ARM/ARMBaseRegisterInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMBaseRegisterInfo.cpp?rev=373738&r1=373737&r2=373738&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMBaseRegisterInfo.cpp (original)
+++ llvm/trunk/lib/Target/ARM/ARMBaseRegisterInfo.cpp Fri Oct  4 05:29:32 2019
@@ -191,7 +191,7 @@ getReservedRegs(const MachineFunction &M
   markSuperRegs(Reserved, ARM::PC);
   markSuperRegs(Reserved, ARM::FPSCR);
   markSuperRegs(Reserved, ARM::APSR_NZCV);
-  if (TFI->hasFP(MF))
+  if (TFI->hasFP(MF) || STI.isTargetDarwin())
     markSuperRegs(Reserved, getFramePointerReg(STI));
   if (hasBasePointer(MF))
     markSuperRegs(Reserved, BasePtr);

Added: llvm/trunk/test/CodeGen/ARM/r7-fixed-darwin.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/ARM/r7-fixed-darwin.ll?rev=373738&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/ARM/r7-fixed-darwin.ll (added)
+++ llvm/trunk/test/CodeGen/ARM/r7-fixed-darwin.ll Fri Oct  4 05:29:32 2019
@@ -0,0 +1,15 @@
+; RUN: llc -mtriple=thumbv7k-apple-watchos %s -o - | FileCheck %s
+
+; r7 is FP on Darwin, and should be preserved even if we don't create a new
+; frame record for this leaf function. So make huge register pressure to try &
+; tempt LLVM to use it.
+define void @foo([16 x i32]* %ptr) {
+; CHECK-LABEL: foo:
+; CHECK: push.w
+; CHECK: .cfi_offset r7
+; CHECK-NOT: r7
+; CHECK: pop.w
+  %val = load volatile [16 x i32], [16 x i32]* %ptr
+  store volatile [16 x i32] %val, [16 x i32]* %ptr
+  ret void
+}

Modified: llvm/trunk/test/CodeGen/Thumb/long.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/Thumb/long.ll?rev=373738&r1=373737&r2=373738&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/Thumb/long.ll (original)
+++ llvm/trunk/test/CodeGen/Thumb/long.ll Fri Oct  4 05:29:32 2019
@@ -234,7 +234,7 @@ if.end:
   %c = add i64 %y, 47
   call void @f13(i64 %c)
 ; CHECK: adds
-; CHECK-NEXT: adcs
+; CHECK: adcs
 ; CHECK: bl
   ret void
 }

Modified: llvm/trunk/test/CodeGen/Thumb2/2010-03-15-AsmCCClobber.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/Thumb2/2010-03-15-AsmCCClobber.ll?rev=373738&r1=373737&r2=373738&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/Thumb2/2010-03-15-AsmCCClobber.ll (original)
+++ llvm/trunk/test/CodeGen/Thumb2/2010-03-15-AsmCCClobber.ll Fri Oct  4 05:29:32 2019
@@ -17,7 +17,7 @@ target datalayout = "e-p:32:32:32-i1:8:3
 ; CHECK: bl _f2
 ; CHECK: clz {{r[0-9]+}}
 ; CHECK-DAG: lsrs    {{r[0-9]+}}
-; CHECK-DAG: lsls    {{r[0-9]+}}
+; CHECK-DAG: lsl.w    {{r[0-9]+}}
 ; CHECK-NEXT: orr.w   {{r[0-9]+}}
 ; CHECK-NEXT: InlineAsm Start
 define void @test(%s1* %this, i32 %format, i32 %w, i32 %h, i32 %levels, i32* %s, i8* %data, i32* nocapture %rowbytes, void (i8*, i8*)* %release, i8* %info) nounwind {