llvm-project/llvm/test/CodeGen/X86/seh-stack-realign.ll

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; RUN: llc -mtriple=i686-windows-msvc < %s | FileCheck %s
; 32-bit catch-all has to use a filter function because that's how it saves the
; exception code.
@str = linkonce_odr unnamed_addr constant [27 x i8] c"GetExceptionCode(): 0x%lx\0A\00", align 1
declare i32 @_except_handler3(...)
declare void @crash()
declare i32 @printf(i8* nocapture readonly, ...) nounwind
declare i32 @llvm.eh.typeid.for(i8*)
declare i8* @llvm.frameaddress(i32)
declare i8* @llvm.localrecover(i8*, i8*, i32)
declare void @llvm.localescape(...)
declare i8* @llvm.x86.seh.recoverfp(i8*, i8*)
define i32 @main() personality i8* bitcast (i32 (...)* @_except_handler3 to i8*) {
entry:
; The EH code allocation is overaligned, triggering realignment.
%__exceptioncode = alloca i32, align 8
call void (...) @llvm.localescape(i32* %__exceptioncode)
invoke void @crash() #5
to label %__try.cont unwind label %lpad
lpad: ; preds = %entry
[IR] Reformulate LLVM's EH funclet IR While we have successfully implemented a funclet-oriented EH scheme on top of LLVM IR, our scheme has some notable deficiencies: - catchendpad and cleanupendpad are necessary in the current design but they are difficult to explain to others, even to seasoned LLVM experts. - catchendpad and cleanupendpad are optimization barriers. They cannot be split and force all potentially throwing call-sites to be invokes. This has a noticable effect on the quality of our code generation. - catchpad, while similar in some aspects to invoke, is fairly awkward. It is unsplittable, starts a funclet, and has control flow to other funclets. - The nesting relationship between funclets is currently a property of control flow edges. Because of this, we are forced to carefully analyze the flow graph to see if there might potentially exist illegal nesting among funclets. While we have logic to clone funclets when they are illegally nested, it would be nicer if we had a representation which forbade them upfront. Let's clean this up a bit by doing the following: - Instead, make catchpad more like cleanuppad and landingpad: no control flow, just a bunch of simple operands; catchpad would be splittable. - Introduce catchswitch, a control flow instruction designed to model the constraints of funclet oriented EH. - Make funclet scoping explicit by having funclet instructions consume the token produced by the funclet which contains them. - Remove catchendpad and cleanupendpad. Their presence can be inferred implicitly using coloring information. N.B. The state numbering code for the CLR has been updated but the veracity of it's output cannot be spoken for. An expert should take a look to make sure the results are reasonable. Reviewers: rnk, JosephTremoulet, andrew.w.kaylor Differential Revision: http://reviews.llvm.org/D15139 llvm-svn: 255422
2015-12-12 13:38:55 +08:00
%cs1 = catchswitch within none [label %__except] unwind to caller
__except: ; preds = %lpad
[IR] Reformulate LLVM's EH funclet IR While we have successfully implemented a funclet-oriented EH scheme on top of LLVM IR, our scheme has some notable deficiencies: - catchendpad and cleanupendpad are necessary in the current design but they are difficult to explain to others, even to seasoned LLVM experts. - catchendpad and cleanupendpad are optimization barriers. They cannot be split and force all potentially throwing call-sites to be invokes. This has a noticable effect on the quality of our code generation. - catchpad, while similar in some aspects to invoke, is fairly awkward. It is unsplittable, starts a funclet, and has control flow to other funclets. - The nesting relationship between funclets is currently a property of control flow edges. Because of this, we are forced to carefully analyze the flow graph to see if there might potentially exist illegal nesting among funclets. While we have logic to clone funclets when they are illegally nested, it would be nicer if we had a representation which forbade them upfront. Let's clean this up a bit by doing the following: - Instead, make catchpad more like cleanuppad and landingpad: no control flow, just a bunch of simple operands; catchpad would be splittable. - Introduce catchswitch, a control flow instruction designed to model the constraints of funclet oriented EH. - Make funclet scoping explicit by having funclet instructions consume the token produced by the funclet which contains them. - Remove catchendpad and cleanupendpad. Their presence can be inferred implicitly using coloring information. N.B. The state numbering code for the CLR has been updated but the veracity of it's output cannot be spoken for. An expert should take a look to make sure the results are reasonable. Reviewers: rnk, JosephTremoulet, andrew.w.kaylor Differential Revision: http://reviews.llvm.org/D15139 llvm-svn: 255422
2015-12-12 13:38:55 +08:00
%p = catchpad within %cs1 [i8* bitcast (i32 ()* @"filt$main" to i8*)]
%code = load i32, i32* %__exceptioncode, align 4
%call = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([27 x i8], [27 x i8]* @str, i32 0, i32 0), i32 %code) #4
[IR] Reformulate LLVM's EH funclet IR While we have successfully implemented a funclet-oriented EH scheme on top of LLVM IR, our scheme has some notable deficiencies: - catchendpad and cleanupendpad are necessary in the current design but they are difficult to explain to others, even to seasoned LLVM experts. - catchendpad and cleanupendpad are optimization barriers. They cannot be split and force all potentially throwing call-sites to be invokes. This has a noticable effect on the quality of our code generation. - catchpad, while similar in some aspects to invoke, is fairly awkward. It is unsplittable, starts a funclet, and has control flow to other funclets. - The nesting relationship between funclets is currently a property of control flow edges. Because of this, we are forced to carefully analyze the flow graph to see if there might potentially exist illegal nesting among funclets. While we have logic to clone funclets when they are illegally nested, it would be nicer if we had a representation which forbade them upfront. Let's clean this up a bit by doing the following: - Instead, make catchpad more like cleanuppad and landingpad: no control flow, just a bunch of simple operands; catchpad would be splittable. - Introduce catchswitch, a control flow instruction designed to model the constraints of funclet oriented EH. - Make funclet scoping explicit by having funclet instructions consume the token produced by the funclet which contains them. - Remove catchendpad and cleanupendpad. Their presence can be inferred implicitly using coloring information. N.B. The state numbering code for the CLR has been updated but the veracity of it's output cannot be spoken for. An expert should take a look to make sure the results are reasonable. Reviewers: rnk, JosephTremoulet, andrew.w.kaylor Differential Revision: http://reviews.llvm.org/D15139 llvm-svn: 255422
2015-12-12 13:38:55 +08:00
catchret from %p to label %__try.cont
__try.cont: ; preds = %entry, %__except
ret i32 0
}
define internal i32 @"filt$main"() {
entry:
%ebp = tail call i8* @llvm.frameaddress(i32 1)
%parentfp = tail call i8* @llvm.x86.seh.recoverfp(i8* bitcast (i32 ()* @main to i8*), i8* %ebp)
%code.i8 = tail call i8* @llvm.localrecover(i8* bitcast (i32 ()* @main to i8*), i8* %parentfp, i32 0)
%__exceptioncode = bitcast i8* %code.i8 to i32*
%info.addr = getelementptr inbounds i8, i8* %ebp, i32 -20
%0 = bitcast i8* %info.addr to i32***
%1 = load i32**, i32*** %0, align 4
%2 = load i32*, i32** %1, align 4
%3 = load i32, i32* %2, align 4
store i32 %3, i32* %__exceptioncode, align 4
ret i32 1
}
; Check that we can get the exception code from eax to the printf.
; CHECK-LABEL: _main:
; CHECK: Lmain$frame_escape_0 = [[code_offs:[-0-9]+]]
; CHECK: movl %esp, [[reg_offs:[-0-9]+]](%esi)
; CHECK: movl $L__ehtable$main,
; EH state 0
; CHECK: movl $0, 40(%esi)
; CHECK: calll _crash
; CHECK: retl
[IR] Reformulate LLVM's EH funclet IR While we have successfully implemented a funclet-oriented EH scheme on top of LLVM IR, our scheme has some notable deficiencies: - catchendpad and cleanupendpad are necessary in the current design but they are difficult to explain to others, even to seasoned LLVM experts. - catchendpad and cleanupendpad are optimization barriers. They cannot be split and force all potentially throwing call-sites to be invokes. This has a noticable effect on the quality of our code generation. - catchpad, while similar in some aspects to invoke, is fairly awkward. It is unsplittable, starts a funclet, and has control flow to other funclets. - The nesting relationship between funclets is currently a property of control flow edges. Because of this, we are forced to carefully analyze the flow graph to see if there might potentially exist illegal nesting among funclets. While we have logic to clone funclets when they are illegally nested, it would be nicer if we had a representation which forbade them upfront. Let's clean this up a bit by doing the following: - Instead, make catchpad more like cleanuppad and landingpad: no control flow, just a bunch of simple operands; catchpad would be splittable. - Introduce catchswitch, a control flow instruction designed to model the constraints of funclet oriented EH. - Make funclet scoping explicit by having funclet instructions consume the token produced by the funclet which contains them. - Remove catchendpad and cleanupendpad. Their presence can be inferred implicitly using coloring information. N.B. The state numbering code for the CLR has been updated but the veracity of it's output cannot be spoken for. An expert should take a look to make sure the results are reasonable. Reviewers: rnk, JosephTremoulet, andrew.w.kaylor Differential Revision: http://reviews.llvm.org/D15139 llvm-svn: 255422
2015-12-12 13:38:55 +08:00
; CHECK: LBB0_[[lpbb:[0-9]+]]: # %__except
; Restore ESP
; CHECK: movl -24(%ebp), %esp
; Restore ESI
; CHECK: leal -44(%ebp), %esi
; Restore EBP
; CHECK: movl 12(%esi), %ebp
; CHECK: movl [[code_offs]](%esi), %[[code:[a-z]+]]
; CHECK-DAG: movl %[[code]], 4(%esp)
; CHECK-DAG: movl $_str, (%esp)
; CHECK: calll _printf
; CHECK: .section .xdata,"dr"
; CHECK: Lmain$parent_frame_offset = [[reg_offs]]
; CHECK: L__ehtable$main
; CHECK-NEXT: .long -1
; CHECK-NEXT: .long _filt$main
; CHECK-NEXT: .long LBB0_[[lpbb]]
; CHECK-LABEL: _filt$main:
; CHECK: pushl %ebp
; CHECK: movl %esp, %ebp
; CHECK: movl (%ebp), %[[oldebp:[a-z]+]]
; CHECK: movl -20(%[[oldebp]]), %[[ehinfo:[a-z]+]]
; CHECK: movl (%[[ehinfo]]), %[[ehrec:[a-z]+]]
; CHECK: movl (%[[ehrec]]), %[[ehcode:[a-z]+]]
; CHECK: movl %[[ehcode]], {{.*}}(%{{.*}})