Update the names of the exception handling sjlj instrinsics to

llvm.eh.sjlj.* for better clarity as to their purpose and scope. Add
a description of llvm.eh.sjlj.setjmp to ExceptionHandling.html.
(llvm.eh.sjlj.longjmp documentation coming when that implementation is
added).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71758 91177308-0d34-0410-b5e6-96231b3b80d8

6 files changed, 44 insertions, 16 deletions

diff --git a/docs/ExceptionHandling.html b/docs/ExceptionHandling.html
index 24a34844c7..7676e09b27 100644
--- a/docs/ExceptionHandling.html
+++ b/docs/ExceptionHandling.html
@@ -31,6 +31,8 @@
   	<li><a href="#llvm_eh_exception"><tt>llvm.eh.exception</tt></a></li>
   	<li><a href="#llvm_eh_selector"><tt>llvm.eh.selector</tt></a></li>
   	<li><a href="#llvm_eh_typeid_for"><tt>llvm.eh.typeid.for</tt></a></li>
+  	<li><a href="#llvm_eh_sjlj_setjmp"><tt>llvm.eh.sjlj.setjmp</tt></a></li>
+  	<li><a href="#llvm_eh_sjlj_longjmp"><tt>llvm.eh.sjlj.longjmp</tt></a></li>
   </ol></li>
   <li><a href="#asm">Asm Table Formats</a>
   <ol>
@@ -401,6 +403,30 @@ a reference to a type info.</p>
 </div>
 
 <!-- ======================================================================= -->
+<div class="doc_subsubsection">
+  <a name="llvm_eh_sjlj_setjmp">llvm.eh.sjlj.setjmp</a>
+</div>
+
+<div class="doc_text">
+<pre>
+  i32 %<a href="#llvm_eh_sjlj_setjmp">llvm.eh.sjlj.setjmp</a>(i8*)
+</pre>
+
+<p>The SJLJ exception handling uses this intrinsic to force register saving
+for the current function and to store the address of the following instruction
+for use as a destination address by <a href="#llvm_eh_sjlj_setjmp">
+<tt>llvm.eh.sjlj.longjmp</tt></a>. The buffer format and the overall functioning
+of this intrinsic is compatible with the GCC <tt>__builtin_setjmp</tt> implementation,
+allowing code built with the two compilers to interoperate.</p>
+
+<p>The single parameter is a pointer to a five word buffer in which the
+calling context is saved. The front end places the frame pointer in the
+first word, and the target implementation of this intrinsic should place the
+destination address for a <a href="#llvm_eh_sjlj_longjmp"><tt>
+    llvm.eh.sjlj.longjmp</tt></a> in the second word. The following three words are available for use in a
+target-specific manner.</p>
+
+<!-- ======================================================================= -->
 <div class="doc_section">
   <a name="asm">Asm Table Formats</a>
 </div>
diff --git a/include/llvm/Intrinsics.td b/include/llvm/Intrinsics.td
index 7c869f0aa3..bce3ce098f 100644
--- a/include/llvm/Intrinsics.td
+++ b/include/llvm/Intrinsics.td
@@ -300,8 +300,8 @@ def int_eh_unwind_init: Intrinsic<[llvm_void_ty]>,
 def int_eh_dwarf_cfa  : Intrinsic<[llvm_ptr_ty], [llvm_i32_ty]>;
 
 let Properties = [IntrNoMem] in {
-def int_builtinsetjmp  : Intrinsic<[llvm_i32_ty],  [llvm_ptr_ty]>;
-def int_builtinlongjmp : Intrinsic<[llvm_void_ty], [llvm_ptr_ty, llvm_i32_ty]>;
+def int_eh_sjlj_setjmp  : Intrinsic<[llvm_i32_ty],  [llvm_ptr_ty]>;
+def int_eh_sjlj_longjmp : Intrinsic<[llvm_void_ty], [llvm_ptr_ty, llvm_i32_ty]>;
 }
 
 //===---------------- Generic Variable Attribute Intrinsics----------------===//
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index f5b33b02ca..d3cf6675f2 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -1045,8 +1045,8 @@ ARMTargetLowering::LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG) {
   default: return SDValue();    // Don't custom lower most intrinsics.
   case Intrinsic::arm_thread_pointer:
       return DAG.getNode(ARMISD::THREAD_POINTER, dl, PtrVT);
-  case Intrinsic::builtinsetjmp:
-      SDValue Res = DAG.getNode(ARMISD::BUILTIN_SETJMP, dl, MVT::i32,
+  case Intrinsic::eh_sjlj_setjmp:
+      SDValue Res = DAG.getNode(ARMISD::EH_SJLJ_SETJMP, dl, MVT::i32,
                          Op.getOperand(1));
       return Res;
   }
diff --git a/lib/Target/ARM/ARMISelLowering.h b/lib/Target/ARM/ARMISelLowering.h
index 32434124d8..0bd492fab6 100644
--- a/lib/Target/ARM/ARMISelLowering.h
+++ b/lib/Target/ARM/ARMISelLowering.h
@@ -64,8 +64,8 @@ namespace llvm {
       FMRRD,        // double to two gprs.
       FMDRR,         // Two gprs to double.
 
-      BUILTIN_SETJMP,   // exception handling setjmp
-      BUILTIN_LONGJMP,  // exception handling longjmp
+      EH_SJLJ_SETJMP,    // SjLj exception handling setjmp
+      EH_SJLJ_LONGJMP,   // SjLj exception handling longjmp
 
       THREAD_POINTER
     };
diff --git a/lib/Target/ARM/ARMInstrInfo.cpp b/lib/Target/ARM/ARMInstrInfo.cpp
index 8e678a8c46..4b0dbb5dac 100644
--- a/lib/Target/ARM/ARMInstrInfo.cpp
+++ b/lib/Target/ARM/ARMInstrInfo.cpp
@@ -991,7 +991,7 @@ unsigned ARMInstrInfo::GetInstSizeInBytes(const MachineInstr *MI) const {
       // If this machine instr is a constant pool entry, its size is recorded as
       // operand #2.
       return MI->getOperand(2).getImm();
-    case ARM::Int_builtin_setjmp: return 12;
+    case ARM::Int_eh_sjlj_setjmp: return 12;
     case ARM::BR_JTr:
     case ARM::BR_JTm:
     case ARM::BR_JTadd:
diff --git a/lib/Target/ARM/ARMInstrInfo.td b/lib/Target/ARM/ARMInstrInfo.td
index cdc0ee55d7..d2e4c34e9c 100644
--- a/lib/Target/ARM/ARMInstrInfo.td
+++ b/lib/Target/ARM/ARMInstrInfo.td
@@ -40,7 +40,7 @@ def SDT_ARMPICAdd  : SDTypeProfile<1, 2, [SDTCisSameAs<0, 1>,
                                           SDTCisPtrTy<1>, SDTCisVT<2, i32>]>;
 
 def SDT_ARMThreadPointer : SDTypeProfile<1, 0, [SDTCisPtrTy<0>]>;
-def SDT_ARMBuiltinSetjmp : SDTypeProfile<1, 1, [SDTCisInt<0>, SDTCisPtrTy<1>]>;
+def SDT_ARMEH_SJLJ_Setjmp : SDTypeProfile<1, 1, [SDTCisInt<0>, SDTCisPtrTy<1>]>;
 
 // Node definitions.
 def ARMWrapper       : SDNode<"ARMISD::Wrapper",     SDTIntUnaryOp>;
@@ -85,7 +85,7 @@ def ARMsra_flag      : SDNode<"ARMISD::SRA_FLAG", SDTIntUnaryOp, [SDNPOutFlag]>;
 def ARMrrx           : SDNode<"ARMISD::RRX"     , SDTIntUnaryOp, [SDNPInFlag ]>;
 
 def ARMthread_pointer: SDNode<"ARMISD::THREAD_POINTER", SDT_ARMThreadPointer>;
-def ARMbuiltin_setjmp: SDNode<"ARMISD::BUILTIN_SETJMP", SDT_ARMBuiltinSetjmp>;
+def ARMeh_sjlj_setjmp: SDNode<"ARMISD::EH_SJLJ_SETJMP", SDT_ARMEH_SJLJ_Setjmp>;
 
 //===----------------------------------------------------------------------===//
 // ARM Instruction Predicate Definitions.
@@ -1269,23 +1269,25 @@ let isCall = 1,
 
 //===----------------------------------------------------------------------===//
 // SJLJ Exception handling intrinsics
-//   setjmp() is a three instruction sequence to store the return address
-//   and save #0 in R0 for the non-longjmp case.
+//   eh_sjlj_setjmp() is a three instruction sequence to store the return 
+//   address and save #0 in R0 for the non-longjmp case.
 //   Since by its nature we may be coming from some other function to get
 //   here, and we're using the stack frame for the containing function to
 //   save/restore registers, we can't keep anything live in regs across
-//   the setjmp(), else it will almost certainly have been tromped upon
+//   the eh_sjlj_setjmp(), else it will almost certainly have been tromped upon
 //   when we get here from a longjmp(). We force everthing out of registers
-//   except for our own input by listing the relevant registers in Defs.
+//   except for our own input by listing the relevant registers in Defs. By
+//   doing so, we also cause the prologue/epilogue code to actively preserve
+//   all of the callee-saved resgisters, which is exactly what we want.
 let Defs = 
   [ R0, R1, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, LR,
     D0, D2, D3, D4, D5, D6, D7, D8, D9, D10, D11, D12, D13, D14, D15 ] in {
-  def Int_builtin_setjmp : XI<(outs), (ins GPR:$src),
+  def Int_eh_sjlj_setjmp : XI<(outs), (ins GPR:$src),
                                AddrModeNone, SizeSpecial, IndexModeNone, Pseudo,
                                "add r0, pc, #4\n\t"
                                "str r0, [$src, #+4]\n\t"
-                               "mov r0, #0 @ setjmp", "",
-                               [(set R0, (ARMbuiltin_setjmp GPR:$src))]>;
+                               "mov r0, #0 @ eh_setjmp", "",
+                               [(set R0, (ARMeh_sjlj_setjmp GPR:$src))]>;
 }
 
 //===----------------------------------------------------------------------===//