Files
llvm/test/CodeGen/WebAssembly/cfg-stackify-eh.ll
T
Heejin Ahn 76db59c4be [WebAssembly] Fix bugs in BLOCK/TRY placement
Summary:
Before we placed all TRY/END_TRY markers before placing BLOCK/END_BLOCK
markers. This couldn't handle this case:
```
bb0:
  br bb2
bb1:          // nearest common dominator of bb3 and bb4
  br_if ... bb3
  br bb4
bb2:
  ...
bb3:
  call @foo   // unwinds to ehpad
bb4:
  call @bar   // unwinds to ehpad
ehpad:
  catch
  ...
```

When we placed TRY markers, we placed it in bb1 because it is the
nearest common dominator of bb3 and bb4. But because bb0 jumps to bb2,
when we placed block markers, we ended up with interleaved scopes like
```
block
try
end_block
catch
end_try
```
which was not correct.

This patch fixes the bug by placing BLOCK and TRY markers in one pass
while iterating BBs in a function. This also adds some more routines to
`placeTryMarkers`, because we now have to assume that there can be
previously placed BLOCK and END_BLOCK.

Reviewers: dschuff

Subscribers: sunfish, sbc100, jgravelle-google, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59739

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357007 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-26 17:15:55 +00:00

349 lines
13 KiB
LLVM

; RUN: llc < %s -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -wasm-keep-registers -disable-block-placement -verify-machineinstrs -fast-isel=false -machine-sink-split-probability-threshold=0 -cgp-freq-ratio-to-skip-merge=1000 -exception-model=wasm -mattr=+exception-handling | FileCheck %s
; RUN: llc < %s -O0 -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -wasm-keep-registers -verify-machineinstrs -exception-model=wasm -mattr=+exception-handling | FileCheck %s --check-prefix=NOOPT
target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
target triple = "wasm32-unknown-unknown"
@_ZTIi = external constant i8*
@_ZTId = external constant i8*
; Simple test case with two catch clauses
;
; void foo();
; void test0() {
; try {
; foo();
; } catch (int) {
; } catch (double) {
; }
; }
; CHECK-LABEL: test0
; CHECK: try
; CHECK: call foo
; CHECK: catch
; CHECK: block
; CHECK: br_if 0, {{.*}} # 0: down to label2
; CHECK: i32.call $drop=, __cxa_begin_catch
; CHECK: call __cxa_end_catch
; CHECK: br 1 # 1: down to label0
; CHECK: end_block # label2:
; CHECK: block
; CHECK: br_if 0, {{.*}} # 0: down to label3
; CHECK: i32.call $drop=, __cxa_begin_catch
; CHECK: call __cxa_end_catch
; CHECK: br 1 # 1: down to label0
; CHECK: end_block # label3:
; CHECK: rethrow {{.*}} # to caller
; CHECK: end_try # label0:
define void @test0() personality i8* bitcast (i32 (...)* @__gxx_wasm_personality_v0 to i8*) {
entry:
invoke void @foo()
to label %try.cont unwind label %catch.dispatch
catch.dispatch: ; preds = %entry
%0 = catchswitch within none [label %catch.start] unwind to caller
catch.start: ; preds = %catch.dispatch
%1 = catchpad within %0 [i8* bitcast (i8** @_ZTIi to i8*), i8* bitcast (i8** @_ZTId to i8*)]
%2 = call i8* @llvm.wasm.get.exception(token %1)
%3 = call i32 @llvm.wasm.get.ehselector(token %1)
%4 = call i32 @llvm.eh.typeid.for(i8* bitcast (i8** @_ZTIi to i8*))
%matches = icmp eq i32 %3, %4
br i1 %matches, label %catch2, label %catch.fallthrough
catch2: ; preds = %catch.start
%5 = call i8* @__cxa_begin_catch(i8* %2) [ "funclet"(token %1) ]
call void @__cxa_end_catch() [ "funclet"(token %1) ]
catchret from %1 to label %try.cont
catch.fallthrough: ; preds = %catch.start
%6 = call i32 @llvm.eh.typeid.for(i8* bitcast (i8** @_ZTId to i8*))
%matches1 = icmp eq i32 %3, %6
br i1 %matches1, label %catch, label %rethrow
catch: ; preds = %catch.fallthrough
%7 = call i8* @__cxa_begin_catch(i8* %2) [ "funclet"(token %1) ]
call void @__cxa_end_catch() [ "funclet"(token %1) ]
catchret from %1 to label %try.cont
rethrow: ; preds = %catch.fallthrough
call void @llvm.wasm.rethrow.in.catch() [ "funclet"(token %1) ]
unreachable
try.cont: ; preds = %catch, %catch2, %entry
ret void
}
; Nested try-catches within a catch
; void test1() {
; try {
; foo();
; } catch (int) {
; try {
; foo();
; } catch (int) {
; foo();
; }
; }
; }
; CHECK-LABEL: test1
; CHECK: try
; CHECK: call foo
; CHECK: catch
; CHECK: block
; CHECK: block
; CHECK: br_if 0, {{.*}} # 0: down to label7
; CHECK: i32.call $drop=, __cxa_begin_catch
; CHECK: try
; CHECK: call foo
; CHECK: br 2 # 2: down to label6
; CHECK: catch
; CHECK: try
; CHECK: block
; CHECK: br_if 0, {{.*}} # 0: down to label11
; CHECK: i32.call $drop=, __cxa_begin_catch
; CHECK: try
; CHECK: call foo
; CHECK: br 2 # 2: down to label9
; CHECK: catch
; CHECK: call __cxa_end_catch
; CHECK: rethrow {{.*}} # down to catch3
; CHECK: end_try
; CHECK: end_block # label11:
; CHECK: rethrow {{.*}} # down to catch3
; CHECK: catch {{.*}} # catch3:
; CHECK: call __cxa_end_catch
; CHECK: rethrow {{.*}} # to caller
; CHECK: end_try # label9:
; CHECK: call __cxa_end_catch
; CHECK: br 2 # 2: down to label6
; CHECK: end_try
; CHECK: end_block # label7:
; CHECK: rethrow {{.*}} # to caller
; CHECK: end_block # label6:
; CHECK: call __cxa_end_catch
; CHECK: end_try
define void @test1() personality i8* bitcast (i32 (...)* @__gxx_wasm_personality_v0 to i8*) {
entry:
invoke void @foo()
to label %try.cont11 unwind label %catch.dispatch
catch.dispatch: ; preds = %entry
%0 = catchswitch within none [label %catch.start] unwind to caller
catch.start: ; preds = %catch.dispatch
%1 = catchpad within %0 [i8* bitcast (i8** @_ZTIi to i8*)]
%2 = call i8* @llvm.wasm.get.exception(token %1)
%3 = call i32 @llvm.wasm.get.ehselector(token %1)
%4 = call i32 @llvm.eh.typeid.for(i8* bitcast (i8** @_ZTIi to i8*))
%matches = icmp eq i32 %3, %4
br i1 %matches, label %catch, label %rethrow
catch: ; preds = %catch.start
%5 = call i8* @__cxa_begin_catch(i8* %2) [ "funclet"(token %1) ]
%6 = bitcast i8* %5 to i32*
%7 = load i32, i32* %6, align 4
invoke void @foo() [ "funclet"(token %1) ]
to label %try.cont unwind label %catch.dispatch2
catch.dispatch2: ; preds = %catch
%8 = catchswitch within %1 [label %catch.start3] unwind label %ehcleanup9
catch.start3: ; preds = %catch.dispatch2
%9 = catchpad within %8 [i8* bitcast (i8** @_ZTIi to i8*)]
%10 = call i8* @llvm.wasm.get.exception(token %9)
%11 = call i32 @llvm.wasm.get.ehselector(token %9)
%12 = call i32 @llvm.eh.typeid.for(i8* bitcast (i8** @_ZTIi to i8*))
%matches4 = icmp eq i32 %11, %12
br i1 %matches4, label %catch6, label %rethrow5
catch6: ; preds = %catch.start3
%13 = call i8* @__cxa_begin_catch(i8* %10) [ "funclet"(token %9) ]
%14 = bitcast i8* %13 to i32*
%15 = load i32, i32* %14, align 4
invoke void @foo() [ "funclet"(token %9) ]
to label %invoke.cont8 unwind label %ehcleanup
invoke.cont8: ; preds = %catch6
call void @__cxa_end_catch() [ "funclet"(token %9) ]
catchret from %9 to label %try.cont
rethrow5: ; preds = %catch.start3
invoke void @llvm.wasm.rethrow.in.catch() [ "funclet"(token %9) ]
to label %unreachable unwind label %ehcleanup9
try.cont: ; preds = %invoke.cont8, %catch
call void @__cxa_end_catch() [ "funclet"(token %1) ]
catchret from %1 to label %try.cont11
rethrow: ; preds = %catch.start
call void @llvm.wasm.rethrow.in.catch() [ "funclet"(token %1) ]
unreachable
try.cont11: ; preds = %try.cont, %entry
ret void
ehcleanup: ; preds = %catch6
%16 = cleanuppad within %9 []
call void @__cxa_end_catch() [ "funclet"(token %16) ]
cleanupret from %16 unwind label %ehcleanup9
ehcleanup9: ; preds = %ehcleanup, %rethrow5, %catch.dispatch2
%17 = cleanuppad within %1 []
call void @__cxa_end_catch() [ "funclet"(token %17) ]
cleanupret from %17 unwind to caller
unreachable: ; preds = %rethrow5
unreachable
}
; Nested loop within a catch clause
; void test2() {
; try {
; foo();
; } catch (...) {
; for (int i = 0; i < 50; i++)
; foo();
; }
; }
; CHECK-LABEL: test2
; CHECK: try
; CHECK: call foo
; CHECK: catch
; CHECK: i32.call $drop=, __cxa_begin_catch
; CHECK: loop # label15:
; CHECK: block
; CHECK: block
; CHECK: br_if 0, {{.*}} # 0: down to label17
; CHECK: try
; CHECK: call foo
; CHECK: br 2 # 2: down to label16
; CHECK: catch
; CHECK: try
; CHECK: call __cxa_end_catch
; CHECK: catch
; CHECK: call __clang_call_terminate
; CHECK: unreachable
; CHECK: end_try
; CHECK: rethrow {{.*}} # to caller
; CHECK: end_try
; CHECK: end_block # label17:
; CHECK: call __cxa_end_catch
; CHECK: br 2 # 2: down to label13
; CHECK: end_block # label16:
; CHECK: br 0 # 0: up to label15
; CHECK: end_loop
; CHECK: end_try # label13:
define void @test2() personality i8* bitcast (i32 (...)* @__gxx_wasm_personality_v0 to i8*) {
entry:
invoke void @foo()
to label %try.cont unwind label %catch.dispatch
catch.dispatch: ; preds = %entry
%0 = catchswitch within none [label %catch.start] unwind to caller
catch.start: ; preds = %catch.dispatch
%1 = catchpad within %0 [i8* null]
%2 = call i8* @llvm.wasm.get.exception(token %1)
%3 = call i32 @llvm.wasm.get.ehselector(token %1)
%4 = call i8* @__cxa_begin_catch(i8* %2) [ "funclet"(token %1) ]
br label %for.cond
for.cond: ; preds = %for.inc, %catch.start
%i.0 = phi i32 [ 0, %catch.start ], [ %inc, %for.inc ]
%cmp = icmp slt i32 %i.0, 50
br i1 %cmp, label %for.body, label %for.end
for.body: ; preds = %for.cond
invoke void @foo() [ "funclet"(token %1) ]
to label %for.inc unwind label %ehcleanup
for.inc: ; preds = %for.body
%inc = add nsw i32 %i.0, 1
br label %for.cond
for.end: ; preds = %for.cond
call void @__cxa_end_catch() [ "funclet"(token %1) ]
catchret from %1 to label %try.cont
try.cont: ; preds = %for.end, %entry
ret void
ehcleanup: ; preds = %for.body
%5 = cleanuppad within %1 []
invoke void @__cxa_end_catch() [ "funclet"(token %5) ]
to label %invoke.cont2 unwind label %terminate
invoke.cont2: ; preds = %ehcleanup
cleanupret from %5 unwind to caller
terminate: ; preds = %ehcleanup
%6 = cleanuppad within %5 []
%7 = call i8* @llvm.wasm.get.exception(token %6)
call void @__clang_call_terminate(i8* %7) [ "funclet"(token %6) ]
unreachable
}
; Tests if block and try markers are correctly placed. Even if two predecessors
; of the EH pad are bb2 and bb3 and their nearest common dominator is bb1, the
; TRY marker should be placed at bb0 because there's a branch from bb0 to bb2,
; and scopes cannot be interleaved.
; NOOPT-LABEL: test3
; NOOPT: try
; NOOPT: block
; NOOPT: block
; NOOPT: block
; NOOPT: end_block
; NOOPT: end_block
; NOOPT: call foo
; NOOPT: end_block
; NOOPT: call bar
; NOOPT: catch {{.*}}
; NOOPT: end_try
define void @test3() personality i8* bitcast (i32 (...)* @__gxx_wasm_personality_v0 to i8*) {
bb0:
br i1 undef, label %bb1, label %bb2
bb1: ; preds = %bb0
br i1 undef, label %bb3, label %bb4
bb2: ; preds = %bb0
br label %try.cont
bb3: ; preds = %bb1
invoke void @foo()
to label %try.cont unwind label %catch.dispatch
bb4: ; preds = %bb1
invoke void @bar()
to label %try.cont unwind label %catch.dispatch
catch.dispatch: ; preds = %bb4, %bb3
%0 = catchswitch within none [label %catch.start] unwind to caller
catch.start: ; preds = %catch.dispatch
%1 = catchpad within %0 [i8* null]
%2 = call i8* @llvm.wasm.get.exception(token %1)
%3 = call i32 @llvm.wasm.get.ehselector(token %1)
catchret from %1 to label %try.cont
try.cont: ; preds = %catch.start, %bb4, %bb3, %bb2
ret void
}
declare void @foo()
declare void @bar()
declare i32 @__gxx_wasm_personality_v0(...)
declare i8* @llvm.wasm.get.exception(token)
declare i32 @llvm.wasm.get.ehselector(token)
declare void @llvm.wasm.rethrow.in.catch()
declare i32 @llvm.eh.typeid.for(i8*)
declare i8* @__cxa_begin_catch(i8*)
declare void @__cxa_end_catch()
declare void @__clang_call_terminate(i8*)
declare void @_ZSt9terminatev()