Add test case for C++ exception handling and fix the following mistakes in MipsFrameLowering::emitPrologue:

- cfi directives are not inserted at the right location or in the right order.
- The source MachineLocation for the cfi directive that changes the cfa register
  to $fp should be MachineLocation::VirtualFP.
- A PROLOG_LABEL that marks the beginning of cfi_offset directives for
  callee-saved register is emitted even when no callee-saved registers are
  saved.
- When a callee-saved double precision register is saved, two cfi_offset
  directives, one for each of the paired single precision registers, should be
  emitted.
 
 


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132703 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/CodeGen/Mips/eh.ll b/test/CodeGen/Mips/eh.ll
new file mode 100644
index 0000000..765b778
--- /dev/null
+++ b/test/CodeGen/Mips/eh.ll
@@ -0,0 +1,78 @@
+; RUN: llc  < %s -march=mipsel -mcpu=4ke | FileCheck %s -check-prefix=CHECK-EL
+; RUN: llc  < %s -march=mips   -mcpu=4ke | FileCheck %s -check-prefix=CHECK-EB
+
+@g1 = global double 0.000000e+00, align 8
+@_ZTId = external constant i8*
+
+define void @_Z1fd(double %i2) {
+entry:
+; CHECK-EL:  addiu $sp, $sp
+; CHECK-EL:  .cfi_def_cfa_offset
+; CHECK-EL:  sdc1 $f20
+; CHECK-EL:  sw  $ra
+; CHECK-EL:  sw  $17
+; CHECK-EL:  sw  $16
+; CHECK-EL:  .cfi_offset 52, -8
+; CHECK-EL:  .cfi_offset 53, -4
+; CHECK-EB:  .cfi_offset 53, -8
+; CHECK-EB:  .cfi_offset 52, -4
+; CHECK-EL:  .cfi_offset 31, -12
+; CHECK-EL:  .cfi_offset 17, -16
+; CHECK-EL:  .cfi_offset 16, -20
+; CHECK-EL:  .cprestore 
+
+  %exception = tail call i8* @__cxa_allocate_exception(i32 8) nounwind
+  %0 = bitcast i8* %exception to double*
+  store double 3.200000e+00, double* %0, align 8, !tbaa !0
+  invoke void @__cxa_throw(i8* %exception, i8* bitcast (i8** @_ZTId to i8*), i8* null) noreturn
+          to label %unreachable unwind label %lpad
+
+lpad:                                             ; preds = %entry
+; CHECK-EL:  # %lpad
+; CHECK-EL:  lw  $gp
+; CHECK-EL:  beq $5
+
+  %exn = tail call i8* @llvm.eh.exception() nounwind
+  %eh.selector = tail call i32 (i8*, i8*, ...)* @llvm.eh.selector(i8* %exn, i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*), i8* bitcast (i8** @_ZTId to i8*)) nounwind
+  %1 = tail call i32 @llvm.eh.typeid.for(i8* bitcast (i8** @_ZTId to i8*)) nounwind
+  %2 = icmp eq i32 %eh.selector, %1
+  br i1 %2, label %catch, label %eh.resume
+
+catch:                                            ; preds = %lpad
+  %3 = tail call i8* @__cxa_begin_catch(i8* %exn) nounwind
+  %4 = bitcast i8* %3 to double*
+  %exn.scalar = load double* %4, align 8
+  %add = fadd double %exn.scalar, %i2
+  store double %add, double* @g1, align 8, !tbaa !0
+  tail call void @__cxa_end_catch() nounwind
+  ret void
+
+eh.resume:                                        ; preds = %lpad
+  tail call void @llvm.eh.resume(i8* %exn, i32 %eh.selector) noreturn
+  unreachable
+
+unreachable:                                      ; preds = %entry
+  unreachable
+}
+
+declare i8* @__cxa_allocate_exception(i32)
+
+declare i8* @llvm.eh.exception() nounwind readonly
+
+declare i32 @__gxx_personality_v0(...)
+
+declare i32 @llvm.eh.selector(i8*, i8*, ...) nounwind
+
+declare i32 @llvm.eh.typeid.for(i8*) nounwind
+
+declare void @llvm.eh.resume(i8*, i32)
+
+declare void @__cxa_throw(i8*, i8*, i8*)
+
+declare i8* @__cxa_begin_catch(i8*)
+
+declare void @__cxa_end_catch()
+
+!0 = metadata !{metadata !"double", metadata !1}
+!1 = metadata !{metadata !"omnipotent char", metadata !2}
+!2 = metadata !{metadata !"Simple C/C++ TBAA", null}