Now Igor, throw the switch...give my creation life!

Use the custom inserter for the ARM setjmp intrinsics. Instead of creating the
SjLj dispatch table in IR, where it frequently violates serveral assumptions --
in particular assumptions made by the landingpad instruction about what can
branch to a landing pad and what cannot. Performing this in the back-end allows
us to violate these assumptions without the IR getting angry at us.

It also allows us to perform a small optimization. We can shove the address of
the dispatch's basic block into the function context and not have to add code
around the setjmp to check for the return value and jump to the dispatch.

Neat, huh?
<rdar://problem/10116753>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142294 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 9 insertions, 4 deletions

diff --git a/lib/CodeGen/SjLjEHPrepare.cpp b/lib/CodeGen/SjLjEHPrepare.cpp
index ded2459..3ccf39b 100644
--- a/lib/CodeGen/SjLjEHPrepare.cpp
+++ b/lib/CodeGen/SjLjEHPrepare.cpp
@@ -36,6 +36,7 @@
 using namespace llvm;
 
 static cl::opt<bool> DisableOldSjLjEH("disable-old-sjlj-eh", cl::Hidden,
+                                      cl::init(true),
     cl::desc("Disable the old SjLj EH preparation pass"));
 
 STATISTIC(NumInvokes, "Number of invokes replaced");
diff --git a/lib/Target/ARM/ARMInstrInfo.td b/lib/Target/ARM/ARMInstrInfo.td
index 2cf0f09..669d268 100644
--- a/lib/Target/ARM/ARMInstrInfo.td
+++ b/lib/Target/ARM/ARMInstrInfo.td
@@ -4635,7 +4635,8 @@ let isCall = 1,
 // no encoding information is necessary.
 let Defs =
   [ R0,  R1,  R2,  R3,  R4,  R5,  R6,  R7,  R8,  R9,  R10, R11, R12, LR, CPSR,
-    QQQQ0, QQQQ1, QQQQ2, QQQQ3 ], hasSideEffects = 1, isBarrier = 1 in {
+    QQQQ0, QQQQ1, QQQQ2, QQQQ3 ], hasSideEffects = 1, isBarrier = 1,
+  usesCustomInserter = 1 in {
   def Int_eh_sjlj_setjmp : PseudoInst<(outs), (ins GPR:$src, GPR:$val),
                                NoItinerary,
                          [(set R0, (ARMeh_sjlj_setjmp GPR:$src, GPR:$val))]>,
diff --git a/lib/Target/ARM/ARMInstrThumb.td b/lib/Target/ARM/ARMInstrThumb.td
index cedb547..c6cc98d 100644
--- a/lib/Target/ARM/ARMInstrThumb.td
+++ b/lib/Target/ARM/ARMInstrThumb.td
@@ -1259,7 +1259,8 @@ def tTPsoft : tPseudoInst<(outs), (ins), 4, IIC_Br,
 // preserve all of the callee-saved resgisters, which is exactly what we want.
 // $val is a scratch register for our use.
 let Defs = [ R0,  R1,  R2,  R3,  R4,  R5,  R6,  R7, R12, CPSR ],
-    hasSideEffects = 1, isBarrier = 1, isCodeGenOnly = 1 in
+    hasSideEffects = 1, isBarrier = 1, isCodeGenOnly = 1,
+    usesCustomInserter = 1 in
 def tInt_eh_sjlj_setjmp : ThumbXI<(outs),(ins tGPR:$src, tGPR:$val),
                                   AddrModeNone, 0, NoItinerary, "","",
                           [(set R0, (ARMeh_sjlj_setjmp tGPR:$src, tGPR:$val))]>;
diff --git a/lib/Target/ARM/ARMInstrThumb2.td b/lib/Target/ARM/ARMInstrThumb2.td
index eb453e7..d03a525 100644
--- a/lib/Target/ARM/ARMInstrThumb2.td
+++ b/lib/Target/ARM/ARMInstrThumb2.td
@@ -3088,7 +3088,8 @@ def t2CLREX : T2I<(outs), (ins), NoItinerary, "clrex", "", []>,
 let Defs =
   [ R0,  R1,  R2,  R3,  R4,  R5,  R6,  R7,  R8,  R9,  R10, R11, R12, LR, CPSR,
     QQQQ0, QQQQ1, QQQQ2, QQQQ3 ],
-  hasSideEffects = 1, isBarrier = 1, isCodeGenOnly = 1 in {
+  hasSideEffects = 1, isBarrier = 1, isCodeGenOnly = 1,
+  usesCustomInserter = 1 in {
   def t2Int_eh_sjlj_setjmp : Thumb2XI<(outs), (ins tGPR:$src, tGPR:$val),
                                AddrModeNone, 0, NoItinerary, "", "",
                           [(set R0, (ARMeh_sjlj_setjmp tGPR:$src, tGPR:$val))]>,
@@ -3097,7 +3098,8 @@ let Defs =
 
 let Defs =
   [ R0,  R1,  R2,  R3,  R4,  R5,  R6,  R7,  R8,  R9,  R10, R11, R12, LR, CPSR ],
-  hasSideEffects = 1, isBarrier = 1, isCodeGenOnly = 1 in {
+  hasSideEffects = 1, isBarrier = 1, isCodeGenOnly = 1,
+  usesCustomInserter = 1 in {
   def t2Int_eh_sjlj_setjmp_nofp : Thumb2XI<(outs), (ins tGPR:$src, tGPR:$val),
                                AddrModeNone, 0, NoItinerary, "", "",
                           [(set R0, (ARMeh_sjlj_setjmp tGPR:$src, tGPR:$val))]>,