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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@373738 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/ARM/ARMBaseRegisterInfo.cpp b/lib/Target/ARM/ARMBaseRegisterInfo.cpp
index 46382816b983996ede728355d1777b7d0466b652..1eaf871867e055675242dc1c7d1c9465aa94a282 100644 (file)
--- a/lib/Target/ARM/ARMBaseRegisterInfo.cpp
+++ b/lib/Target/ARM/ARMBaseRegisterInfo.cpp
@@ -191,7 +191,7 @@ getReservedRegs(const MachineFunction &MF) const {
   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);

diff --git a/test/CodeGen/ARM/r7-fixed-darwin.ll b/test/CodeGen/ARM/r7-fixed-darwin.ll
new file mode 100644 (file)
index 0000000..dc59b6a
--- /dev/null
+++ b/test/CodeGen/ARM/r7-fixed-darwin.ll
@@ -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
+}

diff --git a/test/CodeGen/Thumb/long.ll b/test/CodeGen/Thumb/long.ll
index fbf4b08fd06af20e8716b332f61301b3b4b56dc6..856196af71f55f5480cfb72df5700965a5832b71 100644 (file)
--- a/test/CodeGen/Thumb/long.ll
+++ b/test/CodeGen/Thumb/long.ll
@@ -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
 }

diff --git a/test/CodeGen/Thumb2/2010-03-15-AsmCCClobber.ll b/test/CodeGen/Thumb2/2010-03-15-AsmCCClobber.ll
index b28f4542cf3d22e01ffd98579f8d1d8ea8ccd0fd..b00554af68072577a41b6b3b36072ada80077713 100644 (file)
--- a/test/CodeGen/Thumb2/2010-03-15-AsmCCClobber.ll
+++ b/test/CodeGen/Thumb2/2010-03-15-AsmCCClobber.ll
@@ -17,7 +17,7 @@ target datalayout = "e-p:32:32:32-i1:8:32-i8:8:32-i16:16:32-i32:32:32-i64:32:32-
 ; 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 {