[llvm] r274815 - ARM: support high registers in __builtin_longjmp on WoA

[Saleem Abdulrasool via llvm-commits]

Author: compnerd
Date: Thu Jul  7 19:48:22 2016
New Revision: 274815

URL: http://llvm.org/viewvc/llvm-project?rev=274815&view=rev
Log:
ARM: support high registers in __builtin_longjmp on WoA

Windows on ARM uses a pure thumb-2 environment.  This means that it can select a
high register when doing a __builtin_longjmp.  We would use a tLDRi which would
truncate the register to a low register.  Use a t2LDRi12 to get the full
register file access.  Tweak the code to just load into PC, as that is an
interworking branch on all supported cores anyways.

Modified:
    llvm/trunk/lib/Target/ARM/ARMAsmPrinter.cpp
    llvm/trunk/lib/Target/ARM/ARMBaseInstrInfo.cpp
    llvm/trunk/test/CodeGen/ARM/Windows/builtin_longjmp.ll

Modified: llvm/trunk/lib/Target/ARM/ARMAsmPrinter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMAsmPrinter.cpp?rev=274815&r1=274814&r2=274815&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMAsmPrinter.cpp (original)
+++ llvm/trunk/lib/Target/ARM/ARMAsmPrinter.cpp Thu Jul  7 19:48:22 2016
@@ -1882,8 +1882,7 @@ void ARMAsmPrinter::EmitInstruction(cons
       .addReg(0));
     return;
   }
-  case ARM::tInt_eh_sjlj_longjmp:
-  case ARM::tInt_WIN_eh_sjlj_longjmp: {
+  case ARM::tInt_eh_sjlj_longjmp: {
     // ldr $scratch, [$src, #8]
     // mov sp, $scratch
     // ldr $scratch, [$src, #4]
@@ -1918,7 +1917,7 @@ void ARMAsmPrinter::EmitInstruction(cons
       .addReg(0));
 
     EmitToStreamer(*OutStreamer, MCInstBuilder(ARM::tLDRi)
-      .addReg(Opc == ARM::tInt_WIN_eh_sjlj_longjmp ? ARM::R11 : ARM::R7)
+      .addReg(ARM::R7)
       .addReg(SrcReg)
       .addImm(0)
       // Predicate.
@@ -1932,6 +1931,36 @@ void ARMAsmPrinter::EmitInstruction(cons
       .addReg(0));
     return;
   }
+  case ARM::tInt_WIN_eh_sjlj_longjmp: {
+    // ldr.w r11, [$src, #0]
+    // ldr.w  sp, [$src, #8]
+    // ldr.w  pc, [$src, #4]
+
+    unsigned SrcReg = MI->getOperand(0).getReg();
+
+    EmitToStreamer(*OutStreamer, MCInstBuilder(ARM::t2LDRi12)
+                                     .addReg(ARM::R11)
+                                     .addReg(SrcReg)
+                                     .addImm(0)
+                                     // Predicate
+                                     .addImm(ARMCC::AL)
+                                     .addReg(0));
+    EmitToStreamer(*OutStreamer, MCInstBuilder(ARM::t2LDRi12)
+                                     .addReg(ARM::SP)
+                                     .addReg(SrcReg)
+                                     .addImm(8)
+                                     // Predicate
+                                     .addImm(ARMCC::AL)
+                                     .addReg(0));
+    EmitToStreamer(*OutStreamer, MCInstBuilder(ARM::t2LDRi12)
+                                     .addReg(ARM::PC)
+                                     .addReg(SrcReg)
+                                     .addImm(4)
+                                     // Predicate
+                                     .addImm(ARMCC::AL)
+                                     .addReg(0));
+    return;
+  }
   }
 
   MCInst TmpInst;

Modified: llvm/trunk/lib/Target/ARM/ARMBaseInstrInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMBaseInstrInfo.cpp?rev=274815&r1=274814&r2=274815&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMBaseInstrInfo.cpp (original)
+++ llvm/trunk/lib/Target/ARM/ARMBaseInstrInfo.cpp Thu Jul  7 19:48:22 2016
@@ -648,8 +648,9 @@ unsigned ARMBaseInstrInfo::GetInstSizeIn
   case ARM::Int_eh_sjlj_longjmp:
     return 16;
   case ARM::tInt_eh_sjlj_longjmp:
-  case ARM::tInt_WIN_eh_sjlj_longjmp:
     return 10;
+  case ARM::tInt_WIN_eh_sjlj_longjmp:
+    return 12;
   case ARM::Int_eh_sjlj_setjmp:
   case ARM::Int_eh_sjlj_setjmp_nofp:
     return 20;

Modified: llvm/trunk/test/CodeGen/ARM/Windows/builtin_longjmp.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/ARM/Windows/builtin_longjmp.ll?rev=274815&r1=274814&r2=274815&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/ARM/Windows/builtin_longjmp.ll (original)
+++ llvm/trunk/test/CodeGen/ARM/Windows/builtin_longjmp.ll Thu Jul  7 19:48:22 2016
@@ -9,9 +9,7 @@ entry:
 }
 
 ; CHECK: push.w  {r11, lr}
-; CHECK: ldr     r[[SP:[0-9]+]], [r0, #8]
-; CHECK: mov     sp, r[[SP]]
-; CHECK: ldr     r[[PC:[0-9]+]], [r0, #4]
-; CHECK: ldr     r11, [r0]
-; CHECK: bx      r[[PC]]
+; CHECK: ldr.w   r11, [r0]
+; CHECK: ldr.w   sp, [r0, #8]
+; CHECK: ldr.w   pc, [r0, #4]