Files
clang-p2996/llvm/test/CodeGen/WebAssembly/lower-em-sjlj.ll
Heejin Ahn 173a3a54bb [WebAssembly] Fix SSA rebuilding in SjLj transformation
Summary:
Previously we skipped uses within the same BB as a def when rebuilding
SSA after SjLj transformation. For example, before transformation,
```
for.cond:
  %0 = phi i32 [ %var, %for.inc ] ...
  %var = ...
  br label %for.inc

for.inc:                               ; preds = %for.cond
  call i32 @setjmp(...)
  br %for.cond
```

In this BB, %var should be defined in all paths from %for.inc to make %0
valid. In the input it was true; %for.inc's only predecessor was
%for.cond. But after SjLj transformation, it is possible that %for.inc
has other predecessors that are reachable without reaching %for.cond.
```
entry.split:
  ...
  br i1 %a, label %bb.1, label %for.inc

for.cond:
  %0 = phi i32 [ %var, %for.inc ] ...  ; Not valid!
  %var = ...
  br label %for.inc

for.inc:                               ; preds = %for.cond, %entry.split
  call i32 @setjmp(...)
  ...
  br %for.cond
```

In this case, we can't use %var in the `phi` instruction in %for.cond,
because %var is not defined in all paths through %for.inc (If the
control flow is %entry -> %entry.split -> %for.inc -> %for.cond, %var
has not been defined until we reach the `phi`). But the previous code
excluded users within the same BB, skipping instructions within the same
BB so they are not rewritten properly. User instructions within the same
BB also should be candidates for rewriting if they are _before_ the
original definition.

Fixes PR43097.

Reviewers: dschuff

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

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D66729

llvm-svn: 369978
2019-08-26 21:51:35 +00:00

275 lines
12 KiB
LLVM

; RUN: opt < %s -wasm-lower-em-ehsjlj -S | FileCheck %s
target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
target triple = "wasm32-unknown-unknown"
%struct.__jmp_buf_tag = type { [6 x i32], i32, [32 x i32] }
@global_var = hidden global i32 0, align 4
; CHECK-DAG: __THREW__ = external global i32
; CHECK-DAG: __threwValue = external global i32
; Test a simple setjmp - longjmp sequence
define hidden void @setjmp_longjmp() {
; CHECK-LABEL: @setjmp_longjmp
entry:
%buf = alloca [1 x %struct.__jmp_buf_tag], align 16
%arraydecay = getelementptr inbounds [1 x %struct.__jmp_buf_tag], [1 x %struct.__jmp_buf_tag]* %buf, i32 0, i32 0
%call = call i32 @setjmp(%struct.__jmp_buf_tag* %arraydecay) #0
%arraydecay1 = getelementptr inbounds [1 x %struct.__jmp_buf_tag], [1 x %struct.__jmp_buf_tag]* %buf, i32 0, i32 0
call void @longjmp(%struct.__jmp_buf_tag* %arraydecay1, i32 1) #1
unreachable
; CHECK: entry:
; CHECK-NEXT: %[[MALLOCCALL:.*]] = tail call i8* @malloc(i32 40)
; CHECK-NEXT: %[[SETJMP_TABLE:.*]] = bitcast i8* %[[MALLOCCALL]] to i32*
; CHECK-NEXT: store i32 0, i32* %[[SETJMP_TABLE]]
; CHECK-NEXT: %[[SETJMP_TABLE_SIZE:.*]] = add i32 4, 0
; CHECK-NEXT: %[[BUF:.*]] = alloca [1 x %struct.__jmp_buf_tag]
; CHECK-NEXT: %[[ARRAYDECAY:.*]] = getelementptr inbounds [1 x %struct.__jmp_buf_tag], [1 x %struct.__jmp_buf_tag]* %[[BUF]], i32 0, i32 0
; CHECK-NEXT: %[[SETJMP_TABLE1:.*]] = call i32* @saveSetjmp(%struct.__jmp_buf_tag* %[[ARRAYDECAY]], i32 1, i32* %[[SETJMP_TABLE]], i32 %[[SETJMP_TABLE_SIZE]])
; CHECK-NEXT: %[[SETJMP_TABLE_SIZE1:.*]] = call i32 @getTempRet0()
; CHECK-NEXT: br label %entry.split
; CHECK: entry.split:
; CHECK-NEXT: phi i32 [ 0, %entry ], [ %[[LONGJMP_RESULT:.*]], %if.end ]
; CHECK-NEXT: %[[ARRAYDECAY1:.*]] = getelementptr inbounds [1 x %struct.__jmp_buf_tag], [1 x %struct.__jmp_buf_tag]* %[[BUF]], i32 0, i32 0
; CHECK-NEXT: store i32 0, i32* @__THREW__
; CHECK-NEXT: call cc{{.*}} void @"__invoke_void_%struct.__jmp_buf_tag*_i32"(void (%struct.__jmp_buf_tag*, i32)* @emscripten_longjmp_jmpbuf, %struct.__jmp_buf_tag* %[[ARRAYDECAY1]], i32 1)
; CHECK-NEXT: %[[__THREW__VAL:.*]] = load i32, i32* @__THREW__
; CHECK-NEXT: store i32 0, i32* @__THREW__
; CHECK-NEXT: %[[CMP0:.*]] = icmp ne i32 %__THREW__.val, 0
; CHECK-NEXT: %[[THREWVALUE_VAL:.*]] = load i32, i32* @__threwValue
; CHECK-NEXT: %[[CMP1:.*]] = icmp ne i32 %[[THREWVALUE_VAL]], 0
; CHECK-NEXT: %[[CMP:.*]] = and i1 %[[CMP0]], %[[CMP1]]
; CHECK-NEXT: br i1 %[[CMP]], label %if.then1, label %if.else1
; CHECK: entry.split.split:
; CHECK-NEXT: unreachable
; CHECK: if.then1:
; CHECK-NEXT: %[[__THREW__VAL_I32P:.*]] = inttoptr i32 %[[__THREW__VAL]] to i32*
; CHECK-NEXT: %[[__THREW__VAL_I32P_LOADED:.*]] = load i32, i32* %[[__THREW__VAL_I32P]]
; CHECK-NEXT: %[[LABEL:.*]] = call i32 @testSetjmp(i32 %[[__THREW__VAL_I32P_LOADED]], i32* %[[SETJMP_TABLE1]], i32 %[[SETJMP_TABLE_SIZE1]])
; CHECK-NEXT: %[[CMP:.*]] = icmp eq i32 %[[LABEL]], 0
; CHECK-NEXT: br i1 %[[CMP]], label %if.then2, label %if.end2
; CHECK: if.else1:
; CHECK-NEXT: br label %if.end
; CHECK: if.end:
; CHECK-NEXT: %[[LABEL_PHI:.*]] = phi i32 [ %[[LABEL:.*]], %if.end2 ], [ -1, %if.else1 ]
; CHECK-NEXT: %[[LONGJMP_RESULT]] = call i32 @getTempRet0()
; CHECK-NEXT: switch i32 %[[LABEL_PHI]], label %entry.split.split [
; CHECK-NEXT: i32 1, label %entry.split
; CHECK-NEXT: ]
; CHECK: if.then2:
; CHECK-NEXT: call void @emscripten_longjmp(i32 %[[__THREW__VAL]], i32 %[[THREWVALUE_VAL]])
; CHECK-NEXT: unreachable
; CHECK: if.end2:
; CHECK-NEXT: call void @setTempRet0(i32 %[[THREWVALUE_VAL]])
; CHECK-NEXT: br label %if.end
}
; Test a case of a function call (which is not longjmp) after a setjmp
define hidden void @setjmp_other() {
; CHECK-LABEL: @setjmp_other
entry:
%buf = alloca [1 x %struct.__jmp_buf_tag], align 16
%arraydecay = getelementptr inbounds [1 x %struct.__jmp_buf_tag], [1 x %struct.__jmp_buf_tag]* %buf, i32 0, i32 0
%call = call i32 @setjmp(%struct.__jmp_buf_tag* %arraydecay) #0
call void @foo()
ret void
; CHECK: entry:
; CHECK: %[[SETJMP_TABLE:.*]] = call i32* @saveSetjmp(
; CHECK: entry.split:
; CHECK: @__invoke_void(void ()* @foo)
; CHECK: entry.split.split:
; CHECK-NEXT: %[[BUF:.*]] = bitcast i32* %[[SETJMP_TABLE]] to i8*
; CHECK-NEXT: tail call void @free(i8* %[[BUF]])
; CHECK-NEXT: ret void
}
; Test a case when a function call is within try-catch, after a setjmp
define hidden void @exception_and_longjmp() personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) {
; CHECK-LABEL: @exception_and_longjmp
entry:
%buf = alloca [1 x %struct.__jmp_buf_tag], align 16
%arraydecay = getelementptr inbounds [1 x %struct.__jmp_buf_tag], [1 x %struct.__jmp_buf_tag]* %buf, i32 0, i32 0
%call = call i32 @setjmp(%struct.__jmp_buf_tag* %arraydecay) #0
invoke void @foo()
to label %try.cont unwind label %lpad
; CHECK: entry.split:
; CHECK: store i32 0, i32* @__THREW__
; CHECK-NEXT: call cc{{.*}} void @__invoke_void(void ()* @foo)
; CHECK-NEXT: %[[__THREW__VAL:.*]] = load i32, i32* @__THREW__
; CHECK-NEXT: store i32 0, i32* @__THREW__
; CHECK-NEXT: %[[CMP0:.*]] = icmp ne i32 %[[__THREW__VAL]], 0
; CHECK-NEXT: %[[THREWVALUE_VAL:.*]] = load i32, i32* @__threwValue
; CHECK-NEXT: %[[CMP1:.*]] = icmp ne i32 %[[THREWVALUE_VAL]], 0
; CHECK-NEXT: %[[CMP:.*]] = and i1 %[[CMP0]], %[[CMP1]]
; CHECK-NEXT: br i1 %[[CMP]], label %if.then1, label %if.else1
; CHECK: entry.split.split:
; CHECK-NEXT: %[[CMP:.*]] = icmp eq i32 %[[__THREW__VAL]], 1
; CHECK-NEXT: br i1 %[[CMP]], label %lpad, label %try.cont
lpad: ; preds = %entry
%0 = landingpad { i8*, i32 }
catch i8* null
%1 = extractvalue { i8*, i32 } %0, 0
%2 = extractvalue { i8*, i32 } %0, 1
%3 = call i8* @__cxa_begin_catch(i8* %1) #2
call void @__cxa_end_catch()
br label %try.cont
try.cont: ; preds = %entry, %lpad
ret void
}
; Test SSA validity
define hidden void @ssa(i32 %n) {
; CHECK-LABEL: @ssa
entry:
%buf = alloca [1 x %struct.__jmp_buf_tag], align 16
%cmp = icmp sgt i32 %n, 5
br i1 %cmp, label %if.then, label %if.end
; CHECK: entry:
; CHECK: %[[SETJMP_TABLE0:.*]] = bitcast i8*
; CHECK: %[[SETJMP_TABLE_SIZE0:.*]] = add i32 4, 0
if.then: ; preds = %entry
%0 = load i32, i32* @global_var, align 4
%arraydecay = getelementptr inbounds [1 x %struct.__jmp_buf_tag], [1 x %struct.__jmp_buf_tag]* %buf, i32 0, i32 0
%call = call i32 @setjmp(%struct.__jmp_buf_tag* %arraydecay) #0
store i32 %0, i32* @global_var, align 4
br label %if.end
; CHECK: if.then:
; CHECK: %[[VAR0:.*]] = load i32, i32* @global_var, align 4
; CHECK: %[[SETJMP_TABLE1:.*]] = call i32* @saveSetjmp(
; CHECK-NEXT: %[[SETJMP_TABLE_SIZE1:.*]] = call i32 @getTempRet0()
; CHECK: if.then.split:
; CHECK: %[[VAR1:.*]] = phi i32 [ %[[VAR0]], %if.then ], [ %[[VAR2:.*]], %if.end3 ]
; CHECK: %[[SETJMP_TABLE_SIZE2:.*]] = phi i32 [ %[[SETJMP_TABLE_SIZE1]], %if.then ], [ %[[SETJMP_TABLE_SIZE3:.*]], %if.end3 ]
; CHECK: %[[SETJMP_TABLE2:.*]] = phi i32* [ %[[SETJMP_TABLE1]], %if.then ], [ %[[SETJMP_TABLE3:.*]], %if.end3 ]
; CHECK: store i32 %[[VAR1]], i32* @global_var, align 4
if.end: ; preds = %if.then, %entry
%arraydecay1 = getelementptr inbounds [1 x %struct.__jmp_buf_tag], [1 x %struct.__jmp_buf_tag]* %buf, i32 0, i32 0
call void @longjmp(%struct.__jmp_buf_tag* %arraydecay1, i32 5) #1
unreachable
; CHECK: if.end:
; CHECK: %[[VAR2]] = phi i32 [ %[[VAR1]], %if.then.split ], [ undef, %entry ]
; CHECK: %[[SETJMP_TABLE_SIZE3]] = phi i32 [ %[[SETJMP_TABLE_SIZE2]], %if.then.split ], [ %[[SETJMP_TABLE_SIZE0]], %entry ]
; CHECK: %[[SETJMP_TABLE3]] = phi i32* [ %[[SETJMP_TABLE2]], %if.then.split ], [ %[[SETJMP_TABLE0]], %entry ]
}
; Test a case when a function only calls other functions that are neither setjmp nor longjmp
define hidden void @only_other_func() {
entry:
call void @foo()
ret void
; CHECK: call void @foo()
}
; Test a case when a function only calls longjmp and not setjmp
define hidden void @only_longjmp() {
entry:
%buf = alloca [1 x %struct.__jmp_buf_tag], align 16
%arraydecay = getelementptr inbounds [1 x %struct.__jmp_buf_tag], [1 x %struct.__jmp_buf_tag]* %buf, i32 0, i32 0
call void @longjmp(%struct.__jmp_buf_tag* %arraydecay, i32 5) #1
unreachable
; CHECK: %[[ARRAYDECAY:.*]] = getelementptr inbounds
; CHECK-NEXT: call void @emscripten_longjmp_jmpbuf(%struct.__jmp_buf_tag* %[[ARRAYDECAY]], i32 5)
}
; Test inline asm handling
define hidden void @inline_asm() {
; CHECK-LABEL: @inline_asm
entry:
%env = alloca [1 x %struct.__jmp_buf_tag], align 16
%arraydecay = getelementptr inbounds [1 x %struct.__jmp_buf_tag], [1 x %struct.__jmp_buf_tag]* %env, i32 0, i32 0
%call = call i32 @setjmp(%struct.__jmp_buf_tag* %arraydecay) #4
; Inline assembly should not generate __invoke wrappers.
; Doing so would fail as inline assembly cannot be passed as a function pointer.
; CHECK: call void asm sideeffect "", ""()
; CHECK-NOT: __invoke_void
call void asm sideeffect "", ""()
ret void
}
; Test that the allocsize attribute is being transformed properly
declare i8 *@allocator(i32, %struct.__jmp_buf_tag*) #3
define hidden i8 *@allocsize() {
; CHECK-LABEL: @allocsize
entry:
%buf = alloca [1 x %struct.__jmp_buf_tag], align 16
%arraydecay = getelementptr inbounds [1 x %struct.__jmp_buf_tag], [1 x %struct.__jmp_buf_tag]* %buf, i32 0, i32 0
%call = call i32 @setjmp(%struct.__jmp_buf_tag* %arraydecay) #0
; CHECK: call cc{{.*}} i8* @"__invoke_i8*_i32_%struct.__jmp_buf_tag*"([[ARGS:.*]]) #[[ALLOCSIZE_ATTR:[0-9]+]]
%alloc = call i8* @allocator(i32 20, %struct.__jmp_buf_tag* %arraydecay) #3
ret i8 *%alloc
}
; Tests if program does not crash when there's no setjmp function calls in the
; module.
@buffer = global [1 x %struct.__jmp_buf_tag] zeroinitializer, align 16
define void @longjmp_only() {
entry:
; CHECK: call void @emscripten_longjmp_jmpbuf
call void @longjmp(%struct.__jmp_buf_tag* getelementptr inbounds ([1 x %struct.__jmp_buf_tag], [1 x %struct.__jmp_buf_tag]* @buffer, i32 0, i32 0), i32 1) #1
unreachable
}
; Tests if SSA rewrite works when a use and its def are within the same BB.
define void @ssa_rewite_in_same_bb() {
entry:
call void @foo()
br label %for.cond
for.cond: ; preds = %for.inc, %entry
; CHECK: %{{.*}} = phi i32 [ %var[[VARNO:.*]], %for.inc.split ]
%0 = phi i32 [ %var, %for.inc ], [ undef, %entry ]
%var = add i32 0, 0
br label %for.inc
for.inc: ; preds = %for.cond
%call5 = call i32 @setjmp(%struct.__jmp_buf_tag* undef) #0
br label %for.cond
; CHECK: for.inc.split:
; CHECK: %var[[VARNO]] = phi i32 [ %var, %for.inc ]
}
declare void @foo()
; Function Attrs: returns_twice
declare i32 @setjmp(%struct.__jmp_buf_tag*) #0
; Function Attrs: noreturn
declare void @longjmp(%struct.__jmp_buf_tag*, i32) #1
declare i32 @__gxx_personality_v0(...)
declare i8* @__cxa_begin_catch(i8*)
declare void @__cxa_end_catch()
declare i8* @malloc(i32)
declare void @free(i8*)
; JS glue functions and invoke wrappers declaration
; CHECK-DAG: declare i32 @getTempRet0()
; CHECK-DAG: declare void @setTempRet0(i32)
; CHECK-DAG: declare i32* @saveSetjmp(%struct.__jmp_buf_tag*, i32, i32*, i32)
; CHECK-DAG: declare i32 @testSetjmp(i32, i32*, i32)
; CHECK-DAG: declare void @emscripten_longjmp_jmpbuf(%struct.__jmp_buf_tag*, i32)
; CHECK-DAG: declare void @emscripten_longjmp(i32, i32)
; CHECK-DAG: declare void @__invoke_void(void ()*)
; CHECK-DAG: declare void @"__invoke_void_%struct.__jmp_buf_tag*_i32"(void (%struct.__jmp_buf_tag*, i32)*, %struct.__jmp_buf_tag*, i32)
attributes #0 = { returns_twice }
attributes #1 = { noreturn }
attributes #2 = { nounwind }
attributes #3 = { allocsize(0) }
; CHECK: attributes #[[ALLOCSIZE_ATTR]] = { allocsize(1) }