[PM][FunctionAttrs] add NoUnwind attribute inference to PostOrderFunctionAttrs pass

Summary:
This was motivated by absence of PrunEH functionality in new PM.
It was decided that a proper way to do PruneEH is to add NoUnwind inference
into PostOrderFunctionAttrs and then perform normal SimplifyCFG on top.

This change generalizes attribute handling implemented for (a removal of)
Convergent attribute, by introducing a generic builder-like class
   AttributeInferer

It registers all the attribute inference requests, storing per-attribute
predicates into a vector, and then goes through an SCC Node, scanning all
the instructions for not breaking attribute assumptions.

The main idea is that as soon all the instructions from all the functions
of SCC Node conform to attribute assumptions then we are free to infer
the attribute as set for all the functions of SCC Node.

It handles two distinct cases of attributes:
   - those that might break due to derefinement of the function code

     for these attributes we are allowed to apply inference only if all the
     functions are "exact definitions". Example - NoUnwind.

   - those that do not care about derefinement

     for these attributes we are allowed to apply inference as soon as we see
     any function definition. Example - removal of Convergent attribute.

Also in this commit:
* Converted all the FunctionAttrs tests to use FileCheck and added new-PM
  invocations to them

* FunctionAttrs/convergent.ll test demonstrates a difference in behavior between
   new and old PM implementations. Marked with FIXME.

* PruneEH tests were converted to new-PM as well, using function-attrs+simplify-cfg
  combo as intended

* some of "other" tests were updated since function-attrs now infers 'nounwind'
  even for old PM pipeline

* -disable-nounwind-inference hidden option added as a possible workaround for a supposedly
  rare case when nounwind being inferred by default presents a problem

Reviewers: chandlerc, jlebar

Reviewed By: jlebar

Subscribers: eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D44415

llvm-svn: 328377

21 files changed, 113 insertions, 34 deletions

diff --git a/llvm/test/Transforms/FunctionAttrs/2008-09-03-Mutual.ll b/llvm/test/Transforms/FunctionAttrs/2008-09-03-Mutual.ll
index b0aecfa56f7..6bbd99951ad 100644
--- a/llvm/test/Transforms/FunctionAttrs/2008-09-03-Mutual.ll
+++ b/llvm/test/Transforms/FunctionAttrs/2008-09-03-Mutual.ll
@@ -1,10 +1,17 @@
-; RUN: opt < %s -functionattrs -S | grep readnone
+; RUN: opt < %s -functionattrs -S | FileCheck %s
+; RUN: opt < %s -passes=function-attrs -S | FileCheck %s
 
+; CHECK: Function Attrs
+; CHECK-SAME: readnone
+; CHECK-NEXT: define i32 @a
 define i32 @a() {
 	%tmp = call i32 @b( )		; <i32> [#uses=1]
 	ret i32 %tmp
 }
 
+; CHECK: Function Attrs
+; CHECK-SAME: readnone
+; CHECK-NEXT: define i32 @b
 define i32 @b() {
 	%tmp = call i32 @a( )		; <i32> [#uses=1]
 	ret i32 %tmp
diff --git a/llvm/test/Transforms/FunctionAttrs/2008-09-03-ReadNone.ll b/llvm/test/Transforms/FunctionAttrs/2008-09-03-ReadNone.ll
index b62698a776f..d747fe727fa 100644
--- a/llvm/test/Transforms/FunctionAttrs/2008-09-03-ReadNone.ll
+++ b/llvm/test/Transforms/FunctionAttrs/2008-09-03-ReadNone.ll
@@ -1,25 +1,32 @@
 ; RUN: opt < %s -basicaa -functionattrs -S | FileCheck %s
+; RUN: opt < %s -aa-pipeline=basic-aa -passes=function-attrs -S | FileCheck %s
+
 @x = global i32 0
 
-; CHECK: declare i32 @e() #0
+; CHECK: Function Attrs
+; CHECK-SAME: readnone
+; CHECK-NEXT: declare i32 @e
 declare i32 @e() readnone
 
-; CHECK: define i32 @f() #0
+; CHECK: Function Attrs
+; CHECK-SAME: readnone
+; CHECK-NEXT: define i32 @f
 define i32 @f() {
 	%tmp = call i32 @e( )		; <i32> [#uses=1]
 	ret i32 %tmp
 }
 
-; CHECK: define i32 @g() #1
+; CHECK: Function Attrs
+; CHECK-SAME: readnone
+; CHECK-NEXT: define i32 @g
 define i32 @g() readonly {
 	ret i32 0
 }
 
-; CHECK: define i32 @h() #1
+; CHECK: Function Attrs
+; CHECK-SAME: readnone
+; CHECK-NEXT: define i32 @h
 define i32 @h() readnone {
 	%tmp = load i32, i32* @x		; <i32> [#uses=1]
 	ret i32 %tmp
 }
-
-; CHECK: attributes #0 = { readnone }
-; CHECK: attributes #1 = { norecurse readnone }
diff --git a/llvm/test/Transforms/FunctionAttrs/2008-09-03-ReadOnly.ll b/llvm/test/Transforms/FunctionAttrs/2008-09-03-ReadOnly.ll
index d8256ae8e64..35cb5342d8d 100644
--- a/llvm/test/Transforms/FunctionAttrs/2008-09-03-ReadOnly.ll
+++ b/llvm/test/Transforms/FunctionAttrs/2008-09-03-ReadOnly.ll
@@ -1,4 +1,5 @@
 ; RUN: opt < %s -basicaa -functionattrs -S | FileCheck %s
+; RUN: opt < %s -aa-pipeline=basic-aa -passes=function-attrs -S | FileCheck %s
 
 ; CHECK: define i32 @f() #0
 define i32 @f() {
diff --git a/llvm/test/Transforms/FunctionAttrs/2008-09-13-VolatileRead.ll b/llvm/test/Transforms/FunctionAttrs/2008-09-13-VolatileRead.ll
index fef872c794a..8212e8945ec 100644
--- a/llvm/test/Transforms/FunctionAttrs/2008-09-13-VolatileRead.ll
+++ b/llvm/test/Transforms/FunctionAttrs/2008-09-13-VolatileRead.ll
@@ -1,4 +1,5 @@
-; RUN: opt < %s -functionattrs -S | not grep read
+; RUN: opt < %s -functionattrs -S | FileCheck %s
+; RUN: opt < %s -passes=function-attrs -S | FileCheck %s
 ; PR2792
 
 @g = global i32 0		; <i32*> [#uses=1]
@@ -7,3 +8,5 @@ define i32 @f() {
 	%t = load volatile i32, i32* @g		; <i32> [#uses=1]
 	ret i32 %t
 }
+
+; CHECK-NOT: attributes #{{.*}} read
diff --git a/llvm/test/Transforms/FunctionAttrs/2008-12-29-Constant.ll b/llvm/test/Transforms/FunctionAttrs/2008-12-29-Constant.ll
index e3a8f0161b8..ee1a8caa20e 100644
--- a/llvm/test/Transforms/FunctionAttrs/2008-12-29-Constant.ll
+++ b/llvm/test/Transforms/FunctionAttrs/2008-12-29-Constant.ll
@@ -1,8 +1,12 @@
-; RUN: opt < %s -basicaa -functionattrs -S | grep readnone
+; RUN: opt < %s -basicaa -functionattrs -S | FileCheck %s
+; RUN: opt < %s -aa-pipeline=basic-aa -passes=function-attrs -S | FileCheck %s
 
 @s = external constant i8		; <i8*> [#uses=1]
 
+; CHECK: define i8 @f() #0
 define i8 @f() {
 	%tmp = load i8, i8* @s		; <i8> [#uses=1]
 	ret i8 %tmp
 }
+
+; CHECK: attributes #0 = { {{.*}} readnone
diff --git a/llvm/test/Transforms/FunctionAttrs/2009-01-02-LocalStores.ll b/llvm/test/Transforms/FunctionAttrs/2009-01-02-LocalStores.ll
index 0d0231b42ae..ce72c416563 100644
--- a/llvm/test/Transforms/FunctionAttrs/2009-01-02-LocalStores.ll
+++ b/llvm/test/Transforms/FunctionAttrs/2009-01-02-LocalStores.ll
@@ -1,4 +1,5 @@
 ; RUN: opt < %s -functionattrs -S | FileCheck %s
+; RUN: opt < %s -passes=function-attrs -S | FileCheck %s
 
 ; CHECK: define i32* @a(i32** nocapture readonly %p)
 define i32* @a(i32** %p) {
diff --git a/llvm/test/Transforms/FunctionAttrs/2010-10-30-volatile.ll b/llvm/test/Transforms/FunctionAttrs/2010-10-30-volatile.ll
index 23bb18e92b4..b9536dce8a4 100644
--- a/llvm/test/Transforms/FunctionAttrs/2010-10-30-volatile.ll
+++ b/llvm/test/Transforms/FunctionAttrs/2010-10-30-volatile.ll
@@ -1,12 +1,14 @@
 ; RUN: opt < %s -functionattrs -S | FileCheck %s
+; RUN: opt < %s -passes=function-attrs -S | FileCheck %s
 ; PR8279
 
 @g = constant i32 1
 
+; CHECK: Function Attrs
+; CHECK-SAME: norecurse
+; CHECK-NOT: readonly
+; CHECK-NEXT: void @foo()
 define void @foo() {
-; CHECK: void @foo() #0 {
   %tmp = load volatile i32, i32* @g
   ret void
 }
-
-; CHECK: attributes #0 = { norecurse }
diff --git a/llvm/test/Transforms/FunctionAttrs/assume.ll b/llvm/test/Transforms/FunctionAttrs/assume.ll
index 58200622eab..d6296624a2d 100644
--- a/llvm/test/Transforms/FunctionAttrs/assume.ll
+++ b/llvm/test/Transforms/FunctionAttrs/assume.ll
@@ -1,4 +1,5 @@
 ; RUN: opt -S -o - -functionattrs %s | FileCheck %s
+; RUN: opt -S -o - -passes=function-attrs %s | FileCheck %s
 
 ; CHECK-NOT: readnone
 declare void @llvm.assume(i1)
diff --git a/llvm/test/Transforms/FunctionAttrs/atomic.ll b/llvm/test/Transforms/FunctionAttrs/atomic.ll
index dd915a6027f..af87a28770e 100644
--- a/llvm/test/Transforms/FunctionAttrs/atomic.ll
+++ b/llvm/test/Transforms/FunctionAttrs/atomic.ll
@@ -1,4 +1,5 @@
 ; RUN: opt -basicaa -functionattrs -S < %s | FileCheck %s
+; RUN: opt -aa-pipeline=basic-aa -passes=function-attrs -S < %s | FileCheck %s
 
 ; Atomic load/store to local doesn't affect whether a function is
 ; readnone/readonly.
@@ -19,5 +20,5 @@ entry:
   ret i32 %r
 }
 
-; CHECK: attributes #0 = { norecurse readnone ssp uwtable }
-; CHECK: attributes #1 = { norecurse ssp uwtable }
+; CHECK: attributes #0 = { norecurse nounwind readnone ssp uwtable }
+; CHECK: attributes #1 = { norecurse nounwind ssp uwtable }
diff --git a/llvm/test/Transforms/FunctionAttrs/comdat-ipo.ll b/llvm/test/Transforms/FunctionAttrs/comdat-ipo.ll
index e82d2fb9215..2a149e436b6 100644
--- a/llvm/test/Transforms/FunctionAttrs/comdat-ipo.ll
+++ b/llvm/test/Transforms/FunctionAttrs/comdat-ipo.ll
@@ -1,4 +1,5 @@
 ; RUN: opt < %s -functionattrs -S | FileCheck %s
+; RUN: opt < %s -passes=function-attrs -S | FileCheck %s
 
 ; See PR26774
 
diff --git a/llvm/test/Transforms/FunctionAttrs/convergent.ll b/llvm/test/Transforms/FunctionAttrs/convergent.ll
index 37886b82b87..0e4b7515d01 100644
--- a/llvm/test/Transforms/FunctionAttrs/convergent.ll
+++ b/llvm/test/Transforms/FunctionAttrs/convergent.ll
@@ -1,4 +1,8 @@
-; RUN: opt -functionattrs -S < %s | FileCheck %s
+; FIXME: convert CHECK-INDIRECT into CHECK (and remove -check-prefixes) as soon
+; FIXME: as new-pass-manager's handling of indirect_non_convergent_call is fixed
+;
+; RUN: opt -functionattrs -S < %s | FileCheck %s --check-prefixes=CHECK,CHECK-INDIRECT
+; RUN: opt -passes=function-attrs -S < %s | FileCheck %s
 
 ; CHECK: Function Attrs
 ; CHECK-NOT: convergent
@@ -50,8 +54,8 @@ define i32 @indirect_convergent_call(i32 ()* %f) convergent {
 ; "Function Attrs" comment in the output.
 ;
 ; CHECK: Function Attrs
-; CHECK-NOT: convergent
-; CHECK-NEXT: define i32 @indirect_non_convergent_call(
+; CHECK-INDIRECT-NOT: convergent
+; CHECK-INDIRECT-NEXT: define i32 @indirect_non_convergent_call(
 define i32 @indirect_non_convergent_call(i32 ()* %f) convergent norecurse {
    %a = call i32 %f()
    ret i32 %a
diff --git a/llvm/test/Transforms/FunctionAttrs/int_sideeffect.ll b/llvm/test/Transforms/FunctionAttrs/int_sideeffect.ll
index 13091e3e8cb..24a145908e0 100644
--- a/llvm/test/Transforms/FunctionAttrs/int_sideeffect.ll
+++ b/llvm/test/Transforms/FunctionAttrs/int_sideeffect.ll
@@ -1,17 +1,25 @@
 ; RUN: opt -S < %s -functionattrs | FileCheck %s
+; RUN: opt -S < %s -passes=function-attrs | FileCheck %s
 
+; CHECK: Function Attrs
+; CHECK-SAME: inaccessiblememonly
+; CHECK-NEXT: declare void @llvm.sideeffect()
 declare void @llvm.sideeffect()
 
 ; Don't add readnone or similar attributes when an @llvm.sideeffect() intrinsic
 ; is present.
 
-; CHECK: define void @test() {
+; CHECK: Function Attrs
+; CHECK-NOT: readnone
+; CHECK: define void @test()
 define void @test() {
     call void @llvm.sideeffect()
     ret void
 }
 
-; CHECK: define void @loop() {
+; CHECK: Function Attrs
+; CHECK-NOT: readnone
+; CHECK: define void @loop()
 define void @loop() {
     br label %loop
 
diff --git a/llvm/test/Transforms/FunctionAttrs/nocapture.ll b/llvm/test/Transforms/FunctionAttrs/nocapture.ll
index e137a3800ce..931072e331e 100644
--- a/llvm/test/Transforms/FunctionAttrs/nocapture.ll
+++ b/llvm/test/Transforms/FunctionAttrs/nocapture.ll
@@ -1,4 +1,6 @@
 ; RUN: opt < %s -functionattrs -S | FileCheck %s
+; RUN: opt < %s -passes=function-attrs -S | FileCheck %s
+
 @g = global i32* null		; <i32**> [#uses=1]
 
 ; CHECK: define i32* @c1(i32* readnone returned %q)
diff --git a/llvm/test/Transforms/FunctionAttrs/nonnull-global.ll b/llvm/test/Transforms/FunctionAttrs/nonnull-global.ll
index 43353e82270..d79a7ae290a 100644
--- a/llvm/test/Transforms/FunctionAttrs/nonnull-global.ll
+++ b/llvm/test/Transforms/FunctionAttrs/nonnull-global.ll
@@ -1,4 +1,5 @@
 ; RUN: opt -S -functionattrs %s | FileCheck %s
+; RUN: opt -S -passes=function-attrs %s | FileCheck %s
 
 @a = external global i8, !absolute_symbol !0
 
diff --git a/llvm/test/Transforms/FunctionAttrs/nonnull.ll b/llvm/test/Transforms/FunctionAttrs/nonnull.ll
index 191e6781900..7de65d8a0fd 100644
--- a/llvm/test/Transforms/FunctionAttrs/nonnull.ll
+++ b/llvm/test/Transforms/FunctionAttrs/nonnull.ll
@@ -1,4 +1,6 @@
 ; RUN: opt -S -functionattrs -enable-nonnull-arg-prop %s | FileCheck %s
+; RUN: opt -S -passes=function-attrs -enable-nonnull-arg-prop %s | FileCheck %s
+
 declare nonnull i8* @ret_nonnull()
 
 ; Return a pointer trivially nonnull (call return attribute)
diff --git a/llvm/test/Transforms/FunctionAttrs/norecurse.ll b/llvm/test/Transforms/FunctionAttrs/norecurse.ll
index cd9044d0720..0293938e479 100644
--- a/llvm/test/Transforms/FunctionAttrs/norecurse.ll
+++ b/llvm/test/Transforms/FunctionAttrs/norecurse.ll
@@ -1,53 +1,82 @@
 ; RUN: opt < %s -basicaa -functionattrs -rpo-functionattrs -S | FileCheck %s
 ; RUN: opt < %s -aa-pipeline=basic-aa -passes='cgscc(function-attrs),rpo-functionattrs' -S | FileCheck %s
 
-; CHECK: define i32 @leaf() #0
+; CHECK: Function Attrs
+; CHECK-SAME: norecurse nounwind readnone
+; CHECK-NEXT: define i32 @leaf()
 define i32 @leaf() {
   ret i32 1
 }
 
-; CHECK: define i32 @self_rec() #1
+; CHECK: Function Attrs
+; CHECK-SAME: readnone
+; CHECK-NOT: norecurse
+; CHECK-NEXT: define i32 @self_rec()
 define i32 @self_rec() {
   %a = call i32 @self_rec()
   ret i32 4
 }
 
-; CHECK: define i32 @indirect_rec() #1
+; CHECK: Function Attrs
+; CHECK-SAME: readnone
+; CHECK-NOT: norecurse
+; CHECK-NEXT: define i32 @indirect_rec()
 define i32 @indirect_rec() {
   %a = call i32 @indirect_rec2()
   ret i32 %a
 }
-; CHECK: define i32 @indirect_rec2() #1
+; CHECK: Function Attrs
+; CHECK-SAME: readnone
+; CHECK-NOT: norecurse
+; CHECK-NEXT: define i32 @indirect_rec2()
 define i32 @indirect_rec2() {
   %a = call i32 @indirect_rec()
   ret i32 %a
 }
 
-; CHECK: define i32 @extern() #1
+; CHECK: Function Attrs
+; CHECK-SAME: readnone
+; CHECK-NOT: norecurse
+; CHECK-NEXT: define i32 @extern()
 define i32 @extern() {
   %a = call i32 @k()
   ret i32 %a
 }
+
+; CHECK: Function Attrs
+; CHECK-NEXT: declare i32 @k()
 declare i32 @k() readnone
 
-; CHECK: define void @intrinsic(i8* nocapture %dest, i8* nocapture readonly %src, i32 %len) {
+; CHECK: Function Attrs
+; CHECK-SAME: nounwind
+; CHECK-NOT: norecurse
+; CHECK-NEXT: define void @intrinsic(i8* nocapture %dest, i8* nocapture readonly %src, i32 %len)
 define void @intrinsic(i8* %dest, i8* %src, i32 %len) {
   call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dest, i8* %src, i32 %len, i1 false)
   ret void
 }
+
+; CHECK: Function Attrs
+; CHECK-NEXT: declare void @llvm.memcpy.p0i8.p0i8.i32
 declare void @llvm.memcpy.p0i8.p0i8.i32(i8*, i8*, i32, i1)
 
-; CHECK: define internal i32 @called_by_norecurse() #0
+; CHECK: Function Attrs
+; CHECK-SAME: norecurse readnone
+; CHECK-NEXT: define internal i32 @called_by_norecurse()
 define internal i32 @called_by_norecurse() {
   %a = call i32 @k()
   ret i32 %a
 }
+; CHECK: Function Attrs
+; CHECK-NEXT: define void @m()
 define void @m() norecurse {
   %a = call i32 @called_by_norecurse()
   ret void
 }
 
-; CHECK: define internal i32 @called_by_norecurse_indirectly() #0
+; CHECK: Function Attrs
+; CHECK-SAME: norecurse readnone
+; CHECK-NEXT: define internal i32 @called_by_norecurse_indirectly()
 define internal i32 @called_by_norecurse_indirectly() {
   %a = call i32 @k()
   ret i32 %a
@@ -60,6 +89,3 @@ define void @p() norecurse {
   call void @o()
   ret void
 }
-
-; CHECK: attributes #0 = { norecurse readnone }
-; CHECK: attributes #1 = { readnone }
diff --git a/llvm/test/Transforms/FunctionAttrs/operand-bundles-scc.ll b/llvm/test/Transforms/FunctionAttrs/operand-bundles-scc.ll
index 2502ea719ca..69808a83c6d 100644
--- a/llvm/test/Transforms/FunctionAttrs/operand-bundles-scc.ll
+++ b/llvm/test/Transforms/FunctionAttrs/operand-bundles-scc.ll
@@ -1,13 +1,17 @@
 ; RUN: opt -S -functionattrs < %s | FileCheck %s
+; RUN: opt -S -passes=function-attrs < %s | FileCheck %s
 
 define void @f() {
-; CHECK-LABEL:  define void @f() {
+; CHECK-LABEL:  define void @f() #0 {
  call void @g() [ "unknown"() ]
  ret void
 }
 
 define void @g() {
-; CHECK-LABEL:  define void @g() {
+; CHECK-LABEL:  define void @g() #0 {
  call void @f()
  ret void
 }
+
+
+; CHECK: attributes #0 = { nounwind }
diff --git a/llvm/test/Transforms/FunctionAttrs/optnone.ll b/llvm/test/Transforms/FunctionAttrs/optnone.ll
index cd08c75d75b..586a6d4a081 100644
--- a/llvm/test/Transforms/FunctionAttrs/optnone.ll
+++ b/llvm/test/Transforms/FunctionAttrs/optnone.ll
@@ -1,4 +1,5 @@
 ; RUN: opt < %s -functionattrs -S | FileCheck %s
+; RUN: opt < %s -passes=function-attrs -S | FileCheck %s
 
 @x = global i32 0
 
@@ -19,6 +20,6 @@ declare i8 @strlen(i8*) noinline optnone
 ; CHECK: (i8*) #1
 
 ; CHECK-LABEL: attributes #0
-; CHECK: = { norecurse readnone }
+; CHECK: = { norecurse nounwind readnone }
 ; CHECK-LABEL: attributes #1
 ; CHECK: = { noinline optnone }
diff --git a/llvm/test/Transforms/FunctionAttrs/out-of-bounds-iterator-bug.ll b/llvm/test/Transforms/FunctionAttrs/out-of-bounds-iterator-bug.ll
index db9a895f97e..f2294fe22ef 100644
--- a/llvm/test/Transforms/FunctionAttrs/out-of-bounds-iterator-bug.ll
+++ b/llvm/test/Transforms/FunctionAttrs/out-of-bounds-iterator-bug.ll
@@ -1,4 +1,5 @@
 ; RUN: opt -functionattrs -S < %s | FileCheck %s
+; RUN: opt -passes=function-attrs -S < %s | FileCheck %s
 
 ; This checks for an iterator wraparound bug in FunctionAttrs.  The previous
 ; "incorrect" behavior was inferring readonly for the %x argument in @caller.
diff --git a/llvm/test/Transforms/FunctionAttrs/readnone.ll b/llvm/test/Transforms/FunctionAttrs/readnone.ll
index eddcdd2641d..b5a5b30ae21 100644
--- a/llvm/test/Transforms/FunctionAttrs/readnone.ll
+++ b/llvm/test/Transforms/FunctionAttrs/readnone.ll
@@ -1,4 +1,5 @@
 ; RUN: opt < %s -functionattrs -S | FileCheck %s
+; RUN: opt < %s -passes=function-attrs -S | FileCheck %s
 
 ; CHECK: define void @bar(i8* nocapture readnone)
 define void @bar(i8* readonly) {
diff --git a/llvm/test/Transforms/FunctionAttrs/returned.ll b/llvm/test/Transforms/FunctionAttrs/returned.ll
index ede9481e433..04ddb7b5ac0 100644
--- a/llvm/test/Transforms/FunctionAttrs/returned.ll
+++ b/llvm/test/Transforms/FunctionAttrs/returned.ll
@@ -1,4 +1,5 @@
 ; RUN: opt < %s -functionattrs -S | FileCheck %s
+; RUN: opt < %s -passes=function-attrs -S | FileCheck %s
 
 ; CHECK: define i32 @test1(i32 %p, i32 %q)
 define i32 @test1(i32 %p, i32 %q) {