[PATCH] D84014: AArch64: emit @llvm.debugtrap as `brk 0xf000` on all platforms

[Tim Northover via Phabricator via llvm-commits]

t.p.northover created this revision.
Herald added subscribers: danielkiss, hiraditya, kristof.beyls, mcrosier.
Herald added a project: LLVM.

It's useful for debuggers to be able to distinguish between a `@llvm.trap` (noreturn, so resuming would be a bad idea) and a `@llvm.debugtrap` (a call for attention, resumable).

This is implemented for Windows at the moment, where trap compiles to `brk #1` but debugtrap to `brk #0xf000`. As far as I can tell there's no precedent on other platforms (GCC doesn't have `__builtin_debugtrap`) so I saw no reason to add unneeded platform divergence here and just removed the restriction.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D84014

Files:
  llvm/lib/Target/AArch64/AArch64FastISel.cpp
  llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
  llvm/lib/Target/AArch64/AArch64InstrInfo.td
  llvm/lib/Target/AArch64/GISel/AArch64InstructionSelector.cpp
  llvm/test/CodeGen/AArch64/debugtrap.ll
  llvm/test/CodeGen/AArch64/windows-trap1.ll


Index: llvm/test/CodeGen/AArch64/debugtrap.ll
===================================================================
--- llvm/test/CodeGen/AArch64/debugtrap.ll
+++ llvm/test/CodeGen/AArch64/debugtrap.ll
@@ -1,6 +1,9 @@
 ; RUN: llc -mtriple=aarch64-windows %s -o -| FileCheck %s
 ; RUN: llc -mtriple=aarch64-windows -fast-isel %s -o - | FileCheck %s
 ; RUN: llc -mtriple=aarch64-windows -global-isel %s -o - | FileCheck %s
+; RUN: llc -mtriple=aarch64-linux-gnu %s -o -| FileCheck %s
+; RUN: llc -mtriple=arm64-apple-ios -global-isel %s -o - | FileCheck %s
+; RUN: llc -mtriple=arm64-apple-macosx -fast-isel %s -o - | FileCheck %s
 
 ; CHECK-LABEL: test1:
 ; CHECK: brk #0xf000
Index: llvm/lib/Target/AArch64/GISel/AArch64InstructionSelector.cpp
===================================================================
--- llvm/lib/Target/AArch64/GISel/AArch64InstructionSelector.cpp
+++ llvm/lib/Target/AArch64/GISel/AArch64InstructionSelector.cpp
@@ -4633,8 +4633,6 @@
     MIRBuilder.buildInstr(AArch64::BRK, {}, {}).addImm(1);
     break;
   case Intrinsic::debugtrap:
-    if (!STI.isTargetWindows())
-      return false;
     MIRBuilder.buildInstr(AArch64::BRK, {}, {}).addImm(0xF000);
     break;
   }
Index: llvm/lib/Target/AArch64/AArch64InstrInfo.td
===================================================================
--- llvm/lib/Target/AArch64/AArch64InstrInfo.td
+++ llvm/lib/Target/AArch64/AArch64InstrInfo.td
@@ -6663,7 +6663,7 @@
 
 // __builtin_trap() uses the BRK instruction on AArch64.
 def : Pat<(trap), (BRK 1)>;
-def : Pat<(debugtrap), (BRK 0xF000)>, Requires<[IsWindows]>;
+def : Pat<(debugtrap), (BRK 0xF000)>;
 
 // Multiply high patterns which multiply the lower subvector using smull/umull
 // and the upper subvector with smull2/umull2. Then shuffle the high the high
Index: llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
===================================================================
--- llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -677,8 +677,7 @@
 
   // Trap.
   setOperationAction(ISD::TRAP, MVT::Other, Legal);
-  if (Subtarget->isTargetWindows())
-    setOperationAction(ISD::DEBUGTRAP, MVT::Other, Legal);
+  setOperationAction(ISD::DEBUGTRAP, MVT::Other, Legal);
 
   // We combine OR nodes for bitfield operations.
   setTargetDAGCombine(ISD::OR);
Index: llvm/lib/Target/AArch64/AArch64FastISel.cpp
===================================================================
--- llvm/lib/Target/AArch64/AArch64FastISel.cpp
+++ llvm/lib/Target/AArch64/AArch64FastISel.cpp
@@ -3652,14 +3652,10 @@
     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(AArch64::BRK))
         .addImm(1);
     return true;
-  case Intrinsic::debugtrap: {
-    if (Subtarget->isTargetWindows()) {
-      BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(AArch64::BRK))
-          .addImm(0xF000);
-      return true;
-    }
-    break;
-  }
+  case Intrinsic::debugtrap:
+    BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(AArch64::BRK))
+        .addImm(0xF000);
+    return true;
 
   case Intrinsic::sqrt: {
     Type *RetTy = II->getCalledFunction()->getReturnType();


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