LLVM-1163: AAPCS-VFP violation when CPRC allocated to stack

According to the AAPCS, when a CPRC is allocated to the stack, all other
VFP registers should be marked as unavailable.

I have also modified the rules for allocating non-CPRCs to the stack, to make
it more explicit that all GPRs must be made unavailable. I cannot think of a
case where the old version would produce incorrect answers, so there is no test
for this.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200970 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 18 insertions, 5 deletions

diff --git a/include/llvm/CodeGen/CallingConvLower.h b/include/llvm/CodeGen/CallingConvLower.h
index f824e73433..4bc8cecaff 100644
--- a/include/llvm/CodeGen/CallingConvLower.h
+++ b/include/llvm/CodeGen/CallingConvLower.h
@@ -348,6 +348,15 @@ public:
     return AllocateStack(Size, Align);
   }
 
+  /// Version of AllocateStack with list of extra registers to be shadowed.
+  /// Note that, unlike AllocateReg, this shadows ALL of the shadow registers.
+  unsigned AllocateStack(unsigned Size, unsigned Align,
+                         const uint16_t *ShadowRegs, unsigned NumShadowRegs) {
+    for (unsigned i = 0; i < NumShadowRegs; ++i)
+      MarkAllocated(ShadowRegs[i]);
+    return AllocateStack(Size, Align);
+  }
+
   // HandleByVal - Allocate a stack slot large enough to pass an argument by
   // value. The size and alignment information of the argument is encoded in its
   // parameter attribute.
diff --git a/include/llvm/Target/TargetCallingConv.td b/include/llvm/Target/TargetCallingConv.td
index c1bef28652..9d1dc3837a 100644
--- a/include/llvm/Target/TargetCallingConv.td
+++ b/include/llvm/Target/TargetCallingConv.td
@@ -89,11 +89,15 @@ class CCAssignToStack<int size, int align> : CCAction {
   int Align = align;
 }
 
-/// CCAssignToStackWithShadow - Same as CCAssignToStack, but with a register
-/// to be shadowed.
-class CCAssignToStackWithShadow<int size, int align, Register reg> :
-        CCAssignToStack<size, align> {
-  Register ShadowReg = reg;
+/// CCAssignToStackWithShadow - Same as CCAssignToStack, but with a list of
+/// registers to be shadowed. Note that, unlike CCAssignToRegWithShadow, this
+/// shadows ALL of the registers in shadowList.
+class CCAssignToStackWithShadow<int size,
+                                int align,
+                                list<Register> shadowList> : CCAction {
+  int Size = size;
+  int Align = align;
+  list<Register> ShadowRegList = shadowList;
 }
 
 /// CCPassByVal - This action always matches: it assigns the value to a stack