From d95cd81141a4e398e0d3337cb2e6617281d06278 Mon Sep 17 00:00:00 2001
From: Amara Emerson <amara@apple.com>
Date: Mon, 4 Oct 2021 15:44:27 -0700
Subject: [PATCH] Revert "[GlobalISel][IRTranslator] Emit trap intrinsic for
 "unreachable""

This reverts commit 019041bec32400928ec57b7e3dc1352d896aa5b6.

It broke some bots.
---
 .../include/llvm/CodeGen/GlobalISel/IRTranslator.h |  5 +++--
 llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp       | 22 --------------------
 .../AArch64/GlobalISel/irtranslator-unreachable.ll | 24 ----------------------
 3 files changed, 3 insertions(+), 48 deletions(-)
 delete mode 100644 llvm/test/CodeGen/AArch64/GlobalISel/irtranslator-unreachable.ll

diff --git a/llvm/include/llvm/CodeGen/GlobalISel/IRTranslator.h b/llvm/include/llvm/CodeGen/GlobalISel/IRTranslator.h
index 866a34c..8eab8a5 100644
--- a/llvm/include/llvm/CodeGen/GlobalISel/IRTranslator.h
+++ b/llvm/include/llvm/CodeGen/GlobalISel/IRTranslator.h
@@ -466,8 +466,9 @@ private:
   bool translateSIToFP(const User &U, MachineIRBuilder &MIRBuilder) {
     return translateCast(TargetOpcode::G_SITOFP, U, MIRBuilder);
   }
-  bool translateUnreachable(const User &U, MachineIRBuilder &MIRBuilder);
-
+  bool translateUnreachable(const User &U, MachineIRBuilder &MIRBuilder) {
+    return true;
+  }
   bool translateSExt(const User &U, MachineIRBuilder &MIRBuilder) {
     return translateCast(TargetOpcode::G_SEXT, U, MIRBuilder);
   }
diff --git a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
index ba65b5d..ee4fa8c 100644
--- a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
@@ -2699,28 +2699,6 @@ bool IRTranslator::translateVAArg(const User &U, MachineIRBuilder &MIRBuilder) {
   return true;
 }
 
-bool IRTranslator::translateUnreachable(const User &U, MachineIRBuilder &MIRBuilder) {
-    if (!MF->getTarget().Options.TrapUnreachable)
-    return true;
-
-  auto &UI = cast<UnreachableInst>(U);
-  // We may be able to ignore unreachable behind a noreturn call.
-  if (MF->getTarget().Options.NoTrapAfterNoreturn) {
-    const BasicBlock &BB = *UI.getParent();
-    if (&UI != &BB.front()) {
-      BasicBlock::const_iterator PredI =
-        std::prev(BasicBlock::const_iterator(UI));
-      if (const CallInst *Call = dyn_cast<CallInst>(&*PredI)) {
-        if (Call->doesNotReturn())
-          return true;
-      }
-    }
-  }
-
-  MIRBuilder.buildIntrinsic(Intrinsic::trap, ArrayRef<Register>(), true);
-  return true;
-}
-
 bool IRTranslator::translateInsertElement(const User &U,
                                           MachineIRBuilder &MIRBuilder) {
   // If it is a <1 x Ty> vector, use the scalar as it is
diff --git a/llvm/test/CodeGen/AArch64/GlobalISel/irtranslator-unreachable.ll b/llvm/test/CodeGen/AArch64/GlobalISel/irtranslator-unreachable.ll
deleted file mode 100644
index fe9427d..0000000
--- a/llvm/test/CodeGen/AArch64/GlobalISel/irtranslator-unreachable.ll
+++ /dev/null
@@ -1,24 +0,0 @@
-; NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
-; RUN: llc -O0 -mtriple=aarch64-apple-ios -global-isel -stop-after=irtranslator %s -o - | FileCheck %s
-
-declare void @llvm.trap()
-
-define void @unreachable() {
-  ; CHECK-LABEL: name: unreachable
-  ; CHECK: bb.1 (%ir-block.0):
-  ; CHECK-NEXT:   G_INTRINSIC_W_SIDE_EFFECTS intrinsic(@llvm.trap)
-  unreachable
-  ret void
-}
-
-declare void @foo() noreturn
-define void @trap_call_noreturn() {
-  ; CHECK-LABEL: name: trap_call_noreturn
-  ; CHECK: bb.1 (%ir-block.0):
-  ; CHECK-NEXT:   ADJCALLSTACKDOWN 0, 0, implicit-def $sp, implicit $sp
-  ; CHECK-NEXT:   BL @foo, csr_darwin_aarch64_aapcs, implicit-def $lr, implicit $sp
-  ; CHECK-NEXT:   ADJCALLSTACKUP 0, 0, implicit-def $sp, implicit $sp
-  call void @foo()
-  unreachable
-  ret void
-}
-- 
2.7.4