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Only emit empty inline asm instructions for cond_fail when optimizing. #3743

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Merged
merged 1 commit into from
Jul 27, 2016
Merged

Only emit empty inline asm instructions for cond_fail when optimizing. #3743

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28 changes: 15 additions & 13 deletions lib/IRGen/IRGenSIL.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -4629,19 +4629,21 @@ void IRGenSILFunction::visitCondFailInst(swift::CondFailInst *i) {
Builder.CreateCondBr(cond, failBB, contBB);
Builder.emitBlock(failBB);

// Emit unique side-effecting inline asm calls in order to eliminate
// the possibility that an LLVM optimization or code generation pass
// will merge these blocks back together again. We emit an empty asm
// string with the side-effect flag set, and with a unique integer
// argument for each cond_fail we see in the function.
llvm::IntegerType *asmArgTy = IGM.Int32Ty;
llvm::Type *argTys = { asmArgTy };
llvm::FunctionType *asmFnTy =
llvm::FunctionType::get(IGM.VoidTy, argTys, false /* = isVarArg */);
llvm::InlineAsm *inlineAsm =
llvm::InlineAsm::get(asmFnTy, "", "n", true /* = SideEffects */);
Builder.CreateCall(inlineAsm,
llvm::ConstantInt::get(asmArgTy, NumCondFails++));
if (IGM.IRGen.Opts.Optimize) {
// Emit unique side-effecting inline asm calls in order to eliminate
// the possibility that an LLVM optimization or code generation pass
// will merge these blocks back together again. We emit an empty asm
// string with the side-effect flag set, and with a unique integer
// argument for each cond_fail we see in the function.
llvm::IntegerType *asmArgTy = IGM.Int32Ty;
llvm::Type *argTys = { asmArgTy };
llvm::FunctionType *asmFnTy =
llvm::FunctionType::get(IGM.VoidTy, argTys, false /* = isVarArg */);
llvm::InlineAsm *inlineAsm =
llvm::InlineAsm::get(asmFnTy, "", "n", true /* = SideEffects */);
Builder.CreateCall(inlineAsm,
llvm::ConstantInt::get(asmArgTy, NumCondFails++));
}

// Emit the trap instruction.
llvm::Function *trapIntrinsic =
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21 changes: 19 additions & 2 deletions test/IRGen/condfail.sil
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Original file line number Diff line number Diff line change
@@ -1,12 +1,21 @@
// RUN: %target-swift-frontend -primary-file %s -O -g -S | FileCheck %s --check-prefix=CHECK-%target-cpu
// RUN: %target-swift-frontend -primary-file %s -O -g -S | FileCheck %s --check-prefix CHECK --check-prefix CHECK-%target-cpu --check-prefix CHECK-OPT-%target-os
// RUN: %target-swift-frontend -primary-file %s -g -S | FileCheck %s --check-prefix CHECK --check-prefix CHECK-%target-cpu --check-prefix CHECK-NOOPT-%target-os

import Builtin
import Swift

// Make sure we emit two traps.

// CHECK-LABEL: _test_cond_fail:
// CHECK-LABEL: test_cond_fail:
// CHECK: .cfi_startproc
// CHECK-OPT-macosx: ## InlineAsm Start
// CHECK-OPT-macosx: ## InlineAsm End
// CHECK-OPT-linux: ##APP
// CHECK-OPT-linux: ##NO_APP
// CHECK-NOOPT-macosx-NOT: ## InlineAsm Start
// CHECK-NOOPT-macosx-NOT: ## InlineAsm End
// CHECK-NOOPT-linux-NOT: ##APP
// CHECK-NOOPT-linux-NOT: ##NO_APP
// CHECK-x86_64: ud2
// CHECK-i386: ud2
// CHECK-arm64: brk
Expand All @@ -16,6 +25,14 @@ import Swift
// CHECK-powerpc64le: trap
// CHECK-s390x: trap
// CHECK-NOT: .cfi_endproc
// CHECK-OPT-macosx: ## InlineAsm Start
// CHECK-OPT-macosx: ## InlineAsm End
// CHECK-OPT-linux: ##APP
// CHECK-OPT-linux: ##NO_APP
// CHECK-NOOPT-macosx-NOT: ## InlineAsm Start
// CHECK-NOOPT-macosx-NOT: ## InlineAsm End
// CHECK-NOOPT-linux-NOT: ##APP
// CHECK-NOOPT-linux-NOT: ##NO_APP
// CHECK-x86_64: ud2
// CHECK-i386: ud2
// CHECK-arm64: brk
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