Author: tnorthover Date: Thu Nov 1 06:49:54 2018 New Revision: 345828 URL: http://llvm.org/viewvc/llvm-project?rev=345828&view=rev Log: Logging: make os_log buffer size an integer constant expression.
The size of an os_log buffer is known at any stage of compilation, so making it a constant expression means that the common idiom of declaring a buffer for it won't result in a VLA. That allows the compiler to skip saving and restoring the stack pointer around such buffers. Modified: cfe/trunk/lib/AST/ExprConstant.cpp cfe/trunk/lib/CodeGen/CGBuiltin.cpp cfe/trunk/test/CodeGen/builtins.c Modified: cfe/trunk/lib/AST/ExprConstant.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ExprConstant.cpp?rev=345828&r1=345827&r2=345828&view=diff ============================================================================== --- cfe/trunk/lib/AST/ExprConstant.cpp (original) +++ cfe/trunk/lib/AST/ExprConstant.cpp Thu Nov 1 06:49:54 2018 @@ -33,6 +33,7 @@ // //===----------------------------------------------------------------------===// +#include "clang/Analysis/Analyses/OSLog.h" #include "clang/AST/APValue.h" #include "clang/AST/ASTContext.h" #include "clang/AST/ASTDiagnostic.h" @@ -8126,6 +8127,12 @@ bool IntExprEvaluator::VisitBuiltinCallE llvm_unreachable("unexpected EvalMode"); } + case Builtin::BI__builtin_os_log_format_buffer_size: { + analyze_os_log::OSLogBufferLayout Layout; + analyze_os_log::computeOSLogBufferLayout(Info.Ctx, E, Layout); + return Success(Layout.size().getQuantity(), E); + } + case Builtin::BI__builtin_bswap16: case Builtin::BI__builtin_bswap32: case Builtin::BI__builtin_bswap64: { Modified: cfe/trunk/lib/CodeGen/CGBuiltin.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGBuiltin.cpp?rev=345828&r1=345827&r2=345828&view=diff ============================================================================== --- cfe/trunk/lib/CodeGen/CGBuiltin.cpp (original) +++ cfe/trunk/lib/CodeGen/CGBuiltin.cpp Thu Nov 1 06:49:54 2018 @@ -3609,13 +3609,6 @@ RValue CodeGenFunction::EmitBuiltinExpr( case Builtin::BI__builtin_os_log_format: return emitBuiltinOSLogFormat(*E); - case Builtin::BI__builtin_os_log_format_buffer_size: { - analyze_os_log::OSLogBufferLayout Layout; - analyze_os_log::computeOSLogBufferLayout(CGM.getContext(), E, Layout); - return RValue::get(ConstantInt::get(ConvertType(E->getType()), - Layout.size().getQuantity())); - } - case Builtin::BI__xray_customevent: { if (!ShouldXRayInstrumentFunction()) return RValue::getIgnored(); Modified: cfe/trunk/test/CodeGen/builtins.c URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/builtins.c?rev=345828&r1=345827&r2=345828&view=diff ============================================================================== --- cfe/trunk/test/CodeGen/builtins.c (original) +++ cfe/trunk/test/CodeGen/builtins.c Thu Nov 1 06:49:54 2018 @@ -729,25 +729,28 @@ void test_builtin_os_log_merge_helper1(v // CHECK-LABEL: define void @test_builtin_os_log_errno void test_builtin_os_log_errno() { - // CHECK: %[[VLA:.*]] = alloca i8, i64 4, align 16 - // CHECK: call void @__os_log_helper_16_2_1_0_96(i8* %[[VLA]]) + // CHECK-NOT: @stacksave + // CHECK: %[[BUF:.*]] = alloca [4 x i8], align 1 + // CHECK: %[[DECAY:.*]] = getelementptr inbounds [4 x i8], [4 x i8]* %[[BUF]], i32 0, i32 0 + // CHECK: call void @__os_log_helper_1_2_1_0_96(i8* %[[DECAY]]) + // CHECK-NOT: @stackrestore char buf[__builtin_os_log_format_buffer_size("%m")]; __builtin_os_log_format(buf, "%m"); } -// CHECK-LABEL: define linkonce_odr hidden void @__os_log_helper_16_2_1_0_96 +// CHECK-LABEL: define linkonce_odr hidden void @__os_log_helper_1_2_1_0_96 // CHECK: (i8* %[[BUFFER:.*]]) // CHECK: %[[BUFFER_ADDR:.*]] = alloca i8*, align 8 // CHECK: store i8* %[[BUFFER]], i8** %[[BUFFER_ADDR]], align 8 // CHECK: %[[BUF:.*]] = load i8*, i8** %[[BUFFER_ADDR]], align 8 // CHECK: %[[SUMMARY:.*]] = getelementptr i8, i8* %[[BUF]], i64 0 -// CHECK: store i8 2, i8* %[[SUMMARY]], align 16 +// CHECK: store i8 2, i8* %[[SUMMARY]], align 1 // CHECK: %[[NUMARGS:.*]] = getelementptr i8, i8* %[[BUF]], i64 1 // CHECK: store i8 1, i8* %[[NUMARGS]], align 1 // CHECK: %[[ARGDESCRIPTOR:.*]] = getelementptr i8, i8* %[[BUF]], i64 2 -// CHECK: store i8 96, i8* %[[ARGDESCRIPTOR]], align 2 +// CHECK: store i8 96, i8* %[[ARGDESCRIPTOR]], align 1 // CHECK: %[[ARGSIZE:.*]] = getelementptr i8, i8* %[[BUF]], i64 3 // CHECK: store i8 0, i8* %[[ARGSIZE]], align 1 // CHECK-NEXT: ret void _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits