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[funcattrs] Add the maximal set of implied attributes to definitions 

Have funcattrs expand all implied attributes into the IR. This expands the infrastructure from D100400, but for definitions not declarations this time.

Somewhat subtly, this mostly isn't semantic. Because the accessors did the inference, any client which used the accessor was already getting the stronger result. Clients that directly checked presence of attributes (there are some), will see a stronger result now.

The old behavior can end up quite confusing for two reasons:
* Without this change, we have situations where function-attrs appears to fail when inferring an attribute (as seen by a human reading IR), but that consuming code will see that it should have been implied. As a human trying to sanity check test results and study IR for optimization possibilities, this is exceeding error prone and confusing. (I'll note that I wasted several hours recently because of this.)
* We can have transforms which trigger without the IR appearing (on inspection) to meet the preconditions. This change doesn't prevent this from happening (as the accessors still involve multiple checks), but it should make it less frequent.

I'd argue in favor of deleting the extra checks out of the accessors after this lands, but I want that in it's own review as a) it's purely stylistic, and b) I already know there's some disagreement.

Once this lands, I'm also going to do a cleanup change which will delete some now redundant duplicate predicates in the inference code, but again, that deserves to be a change of it's own.

Differential Revision: https://reviews.llvm.org/D100226
This commit is contained in:
Philip Reames 2021-04-16 14:03:36 -07:00
parent 7c02dc22e4
commit f549176ad9
19 changed files with 64 additions and 68 deletions
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2
clang/test/CodeGenOpenCL/convergent.cl
View File

@ -134,7 +134,7 @@ kernel void assume_convergent_asm()
__asm__ volatile("s_barrier");
}
// CHECK: attributes #0 = { nofree noinline norecurse nounwind willreturn "
// CHECK: attributes #0 = { nofree noinline norecurse nounwind willreturn mustprogress "
// CHECK: attributes #1 = { {{[^}]*}}convergent{{[^}]*}} }
// CHECK: attributes #2 = { {{[^}]*}}convergent{{[^}]*}} }
// CHECK: attributes #3 = { {{[^}]*}}convergent noduplicate{{[^}]*}} }

25
llvm/lib/Transforms/IPO/FunctionAttrs.cpp
View File

@ -57,6 +57,7 @@
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Transforms/IPO.h"
#include "llvm/Transforms/Utils/Local.h"
#include <cassert>
#include <iterator>
#include <map>
@ -1556,21 +1557,7 @@ static bool addNoSyncAttr(const SCCNodeSet &SCCNodes) {
++NumNoSync;
},
/* RequiresExactDefinition= */ true});
bool Changed = AI.run(SCCNodes);
// readnone + not convergent implies nosync
// (This is here so that we don't have to duplicate the function local
// memory reasoning of the readnone analysis.)
for (Function *F : SCCNodes) {
if (!F || F->hasNoSync())
continue;
if (!F->doesNotAccessMemory() || F->isConvergent())
continue;
F->setNoSync();
NumNoSync++;
Changed = true;
}
return Changed;
return AI.run(SCCNodes);
}
static SCCNodesResult createSCCNodeSet(ArrayRef<Function *> Functions) {
@ -1630,6 +1617,14 @@ static bool deriveAttrsInPostOrder(ArrayRef<Function *> Functions,
Changed |= addNoSyncAttr(Nodes.SCCNodes);
// Finally, infer the maximal set of attributes from the ones we've inferred
// above. This is handling the cases where one attribute on a signature
// implies another, but for implementation reasons the inference rule for
// the later is missing (or simply less sophisticated).
for (Function *F : Nodes.SCCNodes)
if (F)
Changed |= inferAttributesFromOthers(*F);
return Changed;
}

12
llvm/test/Analysis/TypeBasedAliasAnalysis/functionattrs.ll
View File

@ -72,13 +72,13 @@ define i32 @test3_no(i8* %p) nounwind {
declare void @callee(i32* %p) nounwind
declare void @llvm.memcpy.p0i8.p0i8.i64(i8*, i8*, i64, i1) nounwind
; CHECK: attributes #0 = { norecurse nosync nounwind readnone willreturn }
; CHECK: attributes #1 = { nofree norecurse nosync nounwind willreturn writeonly }
; CHECK: attributes #2 = { nounwind readonly }
; CHECK: attributes #0 = { nofree norecurse nosync nounwind readnone willreturn mustprogress }
; CHECK: attributes #1 = { nofree norecurse nosync nounwind willreturn writeonly mustprogress }
; CHECK: attributes #2 = { nofree nounwind readonly }
; CHECK: attributes #3 = { nounwind }
; CHECK: attributes #4 = { nosync nounwind readnone willreturn }
; CHECK: attributes #5 = { nofree nosync nounwind willreturn }
; CHECK: attributes #6 = { nofree norecurse nosync nounwind willreturn }
; CHECK: attributes #4 = { nofree nosync nounwind readnone willreturn mustprogress }
; CHECK: attributes #5 = { nofree nosync nounwind willreturn mustprogress }
; CHECK: attributes #6 = { nofree norecurse nosync nounwind willreturn mustprogress }
; CHECK: attributes #7 = { argmemonly nofree nosync nounwind willreturn }
; Root note.

12
llvm/test/CodeGen/AMDGPU/inline-attr.ll
View File

@ -6,14 +6,14 @@
; GCN: define amdgpu_kernel void @caller(float addrspace(1)* nocapture %p) local_unnamed_addr #1 {
; GCN: %mul.i = fmul float %load, 1.500000e+01
; UNSAFE: attributes #0 = { norecurse nosync nounwind readnone willreturn "unsafe-fp-math"="true" }
; UNSAFE: attributes #1 = { nofree norecurse nosync nounwind willreturn "less-precise-fpmad"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "unsafe-fp-math"="true" }
; UNSAFE: attributes #0 = { nofree norecurse nosync nounwind readnone willreturn mustprogress "unsafe-fp-math"="true" }
; UNSAFE: attributes #1 = { nofree norecurse nosync nounwind willreturn mustprogress "less-precise-fpmad"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "unsafe-fp-math"="true" }
; NOINFS: attributes #0 = { norecurse nosync nounwind readnone willreturn "no-infs-fp-math"="true" }
; NOINFS: attributes #1 = { nofree norecurse nosync nounwind willreturn "less-precise-fpmad"="false" "no-infs-fp-math"="true" "no-nans-fp-math"="false" "unsafe-fp-math"="false" }
; NOINFS: attributes #0 = { nofree norecurse nosync nounwind readnone willreturn mustprogress "no-infs-fp-math"="true" }
; NOINFS: attributes #1 = { nofree norecurse nosync nounwind willreturn mustprogress "less-precise-fpmad"="false" "no-infs-fp-math"="true" "no-nans-fp-math"="false" "unsafe-fp-math"="false" }
; NONANS: attributes #0 = { norecurse nosync nounwind readnone willreturn "no-nans-fp-math"="true" }
; NONANS: attributes #1 = { nofree norecurse nosync nounwind willreturn "less-precise-fpmad"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="true" "unsafe-fp-math"="false" }
; NONANS: attributes #0 = { nofree norecurse nosync nounwind readnone willreturn mustprogress "no-nans-fp-math"="true" }
; NONANS: attributes #1 = { nofree norecurse nosync nounwind willreturn mustprogress "less-precise-fpmad"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="true" "unsafe-fp-math"="false" }
define float @foo(float %x) #0 {
entry:

10
llvm/test/Other/cgscc-devirt-iteration.ll
View File

@ -28,7 +28,7 @@ declare void @unknown()
define void @test1() {
; BEFORE-NOT: Function Attrs
; AFTER: Function Attrs: nosync readnone
; AFTER: Function Attrs: nofree nosync readnone
; CHECK-LABEL: define void @test1()
entry:
%fptr = alloca void ()*
@ -56,8 +56,8 @@ declare void @readnone_with_arg(void ()**) readnone
define void @test2_a(void ()** %ignore) {
; BEFORE-NOT: Function Attrs
; AFTER1: Function Attrs: readonly
; AFTER2: Function Attrs: nosync readnone
; AFTER1: Function Attrs: nofree readonly
; AFTER2: Function Attrs: nofree nosync readnone
; BEFORE: define void @test2_a(void ()** %ignore)
; AFTER: define void @test2_a(void ()** readnone %ignore)
entry:
@ -77,8 +77,8 @@ entry:
define void @test2_b() {
; BEFORE-NOT: Function Attrs
; AFTER1: Function Attrs: readonly
; AFTER2: Function Attrs: nosync readnone
; AFTER1: Function Attrs: nofree readonly
; AFTER2: Function Attrs: nofree nosync readnone
; CHECK-LABEL: define void @test2_b()
entry:
%f2ptr = alloca void ()*

6
llvm/test/Other/cgscc-iterate-function-mutation.ll
View File

@ -1,8 +1,8 @@
; RUN: opt -aa-pipeline=basic-aa -passes='cgscc(function-attrs,function(simplify-cfg))' -S < %s | FileCheck %s
declare void @readnone() nosync readnone
declare void @readnone() nofree nosync readnone
declare void @unknown()
declare void @reference_function_pointer(void()*) nosync readnone
declare void @reference_function_pointer(void()*) nofree nosync readnone
; The @test1_* set of functions checks that when we mutate functions with
; simplify-cfg to delete call edges and this ends up splitting both the SCCs
@ -338,4 +338,4 @@ exit:
ret void
}
; CHECK: attributes #0 = { nosync readnone }
; CHECK: attributes #0 = { nofree nosync readnone }

4
llvm/test/Other/cgscc-observe-devirt.ll
View File

@ -10,7 +10,7 @@
; without requiring the outer manager to iterate doesn't break any invariant.
; RUN: opt -aa-pipeline=basic-aa -passes='cgscc(function-attrs,function(gvn),function-attrs)' -S < %s | FileCheck %s --check-prefix=AFTER
declare void @readnone() nosync readnone
declare void @readnone() nofree nosync readnone
declare void @unknown()
; The @test1_* checks that if we refine an indirect call to a direct call and
@ -103,4 +103,4 @@ define void @test2_b3() {
ret void
}
; CHECK: attributes #0 = { nosync readnone }
; CHECK: attributes #0 = { nofree nosync readnone }

5
llvm/test/Transforms/FunctionAttrs/2008-09-03-ReadOnly.ll
View File

@ -8,7 +8,8 @@ entry:
ret i32 %tmp
}
; CHECK: declare i32 @e() #0
; CHECK: declare i32 @e() #1
declare i32 @e() readonly
; CHECK: attributes #0 = { readonly }
; CHECK: attributes #0 = { nofree readonly }
; CHECK: attributes #1 = { readonly }

4
llvm/test/Transforms/FunctionAttrs/atomic.ll
View File

@ -20,5 +20,5 @@ entry:
ret i32 %r
}
; CHECK: attributes #0 = { norecurse nosync nounwind readnone ssp uwtable willreturn }
; CHECK: attributes #1 = { nofree norecurse nounwind ssp uwtable willreturn }
; CHECK: attributes #0 = { nofree norecurse nosync nounwind readnone ssp uwtable willreturn mustprogress }
; CHECK: attributes #1 = { nofree norecurse nounwind ssp uwtable willreturn mustprogress }

2
llvm/test/Transforms/FunctionAttrs/incompatible_fn_attrs.ll
View File

@ -28,5 +28,5 @@ entry:
attributes #0 = { argmemonly }
attributes #1 = { inaccessiblememonly }
attributes #2 = { inaccessiblemem_or_argmemonly }
; CHECK: attributes #0 = { norecurse nosync nounwind readnone willreturn }
; CHECK: attributes #0 = { nofree norecurse nosync nounwind readnone willreturn mustprogress }
; CHECK-NOT: attributes

10
llvm/test/Transforms/FunctionAttrs/nofree-attributor.ll
View File

@ -12,7 +12,7 @@ declare void @_ZdaPv(i8*) local_unnamed_addr #2
; TEST 1 (positive case)
; FNATTR: Function Attrs: noinline norecurse nosync nounwind readnone uwtable
; FNATTR: Function Attrs: nofree noinline norecurse nosync nounwind readnone uwtable
; FNATTR-NEXT: define void @only_return()
define void @only_return() #0 {
ret void
@ -78,14 +78,14 @@ end:
; }
; FNATTR: Function Attrs: noinline nosync nounwind readnone uwtable
; FNATTR: Function Attrs: nofree noinline nosync nounwind readnone uwtable
; FNATTR-NEXT: define void @mutual_recursion1()
define void @mutual_recursion1() #0 {
call void @mutual_recursion2()
ret void
}
; FNATTR: Function Attrs: noinline nosync nounwind readnone uwtable
; FNATTR: Function Attrs: nofree noinline nosync nounwind readnone uwtable
; FNATTR-NEXT: define void @mutual_recursion2()
define void @mutual_recursion2() #0 {
call void @mutual_recursion1()
@ -132,7 +132,7 @@ define noalias i8* @call_realloc(i8* nocapture %0, i64 %1) local_unnamed_addr #0
; FNATTR-NEXT: declare void @nofree_function()
declare void @nofree_function() nofree readnone #0
; FNATTR: Function Attrs: noinline nosync nounwind readnone uwtable
; FNATTR: Function Attrs: nofree noinline nosync nounwind readnone uwtable
; FNATTR-NEXT: define void @call_nofree_function()
define void @call_nofree_function() #0 {
tail call void @nofree_function()
@ -168,7 +168,7 @@ define void @call_both() #0 {
; TEST 10 (positive case)
; Call intrinsic function
; FNATTRS: Function Attrs: noinline nosync readnone speculatable
; FNATTRS: Function Attrs: nofree noinline nosync readnone speculatable
; FNATTRS-NEXT: declare float @llvm.floor.f32(float %0)
declare float @llvm.floor.f32(float)

2
llvm/test/Transforms/FunctionAttrs/nofree.ll
View File

@ -36,7 +36,7 @@ entry:
declare void @free(i8* nocapture) local_unnamed_addr #2
define i32 @_Z4foo3Pi(i32* nocapture readonly %a) local_unnamed_addr #3 {
; CHECK: Function Attrs: norecurse nosync nounwind readonly uwtable willreturn
; CHECK: Function Attrs: nofree norecurse nosync nounwind readonly uwtable willreturn
; CHECK-LABEL: @_Z4foo3Pi(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[TMP0:%.*]] = load i32, i32* [[A:%.*]], align 4

12
llvm/test/Transforms/FunctionAttrs/nosync.ll
View File

@ -6,7 +6,7 @@ target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
; Base case, empty function
define void @test1() {
; CHECK: Function Attrs: norecurse nosync nounwind readnone willreturn
; CHECK: Function Attrs: nofree norecurse nosync nounwind readnone willreturn
; CHECK-LABEL: @test1(
; CHECK-NEXT: ret void
;
@ -15,7 +15,7 @@ define void @test1() {
; Show the bottom up walk
define void @test2() {
; CHECK: Function Attrs: norecurse nosync nounwind readnone willreturn
; CHECK: Function Attrs: nofree norecurse nosync nounwind readnone willreturn
; CHECK-LABEL: @test2(
; CHECK-NEXT: call void @test1()
; CHECK-NEXT: ret void
@ -38,7 +38,7 @@ define void @test3() convergent {
}
define i32 @test4(i32 %a, i32 %b) {
; CHECK: Function Attrs: norecurse nosync nounwind readnone willreturn
; CHECK: Function Attrs: nofree norecurse nosync nounwind readnone willreturn
; CHECK-LABEL: @test4(
; CHECK-NEXT: [[ADD:%.*]] = add i32 [[A:%.*]], [[B:%.*]]
; CHECK-NEXT: ret i32 [[A]]
@ -137,7 +137,7 @@ define i32 @load_acquire(i32* nocapture readonly %0) norecurse nounwind uwtable
}
define i32 @load_unordered(i32* nocapture readonly %0) norecurse nounwind uwtable {
; CHECK: Function Attrs: norecurse nosync nounwind readonly uwtable willreturn
; CHECK: Function Attrs: nofree norecurse nosync nounwind readonly uwtable willreturn
; CHECK-LABEL: @load_unordered(
; CHECK-NEXT: [[TMP2:%.*]] = load atomic i32, i32* [[TMP0:%.*]] unordered, align 4
; CHECK-NEXT: ret i32 [[TMP2]]
@ -271,7 +271,7 @@ declare void @readnone_test() convergent readnone
; negative. Convergent
define void @convergent_readnone(){
; CHECK: Function Attrs: nosync readnone
; CHECK: Function Attrs: nofree nosync readnone
; CHECK-LABEL: @convergent_readnone(
; CHECK-NEXT: call void @readnone_test()
; CHECK-NEXT: ret void
@ -299,7 +299,7 @@ define void @i_totally_sync() {
declare float @llvm.cos(float %val) readnone
define float @cos_test(float %x) {
; CHECK: Function Attrs: nosync nounwind readnone willreturn
; CHECK: Function Attrs: nofree nosync nounwind readnone willreturn
; CHECK-LABEL: @cos_test(
; CHECK-NEXT: [[C:%.*]] = call float @llvm.cos.f32(float [[X:%.*]])
; CHECK-NEXT: ret float [[C]]

6
llvm/test/Transforms/FunctionAttrs/nounwind.ll
View File

@ -1,14 +1,14 @@
; RUN: opt < %s -function-attrs -S | FileCheck %s
; TEST 1
; CHECK: Function Attrs: norecurse nosync nounwind readnone
; CHECK: Function Attrs: nofree norecurse nosync nounwind readnone
; CHECK-NEXT: define i32 @foo1()
define i32 @foo1() {
ret i32 1
}
; TEST 2
; CHECK: Function Attrs: nosync nounwind readnone
; CHECK: Function Attrs: nofree nosync nounwind readnone
; CHECK-NEXT: define i32 @scc1_foo()
define i32 @scc1_foo() {
%1 = call i32 @scc1_bar()
@ -17,7 +17,7 @@ define i32 @scc1_foo() {
; TEST 3
; CHECK: Function Attrs: nosync nounwind readnone
; CHECK: Function Attrs: nofree nosync nounwind readnone
; CHECK-NEXT: define i32 @scc1_bar()
define i32 @scc1_bar() {
%1 = call i32 @scc1_foo()

2
llvm/test/Transforms/FunctionAttrs/optnone.ll
View File

@ -20,6 +20,6 @@ declare i8 @strlen(i8*) noinline optnone
; CHECK: (i8*) #1
; CHECK-LABEL: attributes #0
; CHECK: = { norecurse nosync nounwind readnone willreturn }
; CHECK: = { nofree norecurse nosync nounwind readnone willreturn mustprogress }
; CHECK-LABEL: attributes #1
; CHECK: = { noinline optnone }

2
llvm/test/Transforms/FunctionAttrs/willreturn-callsites.ll
View File

@ -38,7 +38,7 @@ define void @test_fn_willreturn(i32* %ptr) willreturn {
}
define void @test_fn_mustprogress_readonly_calls(i32* %ptr) mustprogress {
; CHECK: Function Attrs: readonly willreturn mustprogress
; CHECK: Function Attrs: nofree readonly willreturn mustprogress
; CHECK-LABEL: @test_fn_mustprogress_readonly_calls(
; CHECK-NOT: call void @decl_readonly() #
; CHECK-NOT: call void @decl_readnone() #

2
llvm/test/Transforms/FunctionAttrs/writeonly.ll
View File

@ -27,4 +27,4 @@ nouses-argworn-funwo_entry:
; CHECK: attributes #0 = { {{.*}} readnone {{.*}} }
; CHECK: attributes #1 = { {{.*}} readonly {{.*}} }
; CHECK: attributes #2 = { {{.*}} writeonly }
; CHECK: attributes #2 = { {{.*}} writeonly {{.*}} }

2
llvm/test/Transforms/InferFunctionAttrs/norecurse_debug.ll
View File

@ -52,5 +52,5 @@ attributes #1 = { nounwind readnone speculatable }
!28 = !DILocation(line: 9, column: 18, scope: !2)
!29 = !DILocation(line: 10, column: 1, scope: !2)
; CHECK: attributes #0 = { nofree norecurse nosync nounwind willreturn }
; CHECK: attributes #0 = { nofree norecurse nosync nounwind willreturn mustprogress }
; CHECK-NOT: foo.coefficient1

12
llvm/test/Transforms/Inline/cgscc-update.ll
View File

@ -27,7 +27,7 @@ entry:
}
; This function should have had 'readnone' deduced for its SCC.
; CHECK: Function Attrs: noinline nosync nounwind readnone
; CHECK: Function Attrs: nofree noinline nosync nounwind readnone
; CHECK-NEXT: define void @test1_g()
define void @test1_g() noinline {
entry:
@ -36,7 +36,7 @@ entry:
}
; This function should have had 'readnone' deduced for its SCC.
; CHECK: Function Attrs: noinline nosync nounwind readnone
; CHECK: Function Attrs: nofree noinline nosync nounwind readnone
; CHECK-NEXT: define void @test1_h()
define void @test1_h() noinline {
entry:
@ -59,7 +59,7 @@ entry:
}
; This function should have had 'readnone' deduced for its SCC.
; CHECK: Function Attrs: noinline nosync nounwind readnone
; CHECK: Function Attrs: nofree noinline nosync nounwind readnone
; CHECK-NEXT: define void @test2_g()
define void @test2_g() noinline {
entry:
@ -69,7 +69,7 @@ entry:
}
; This function should have had 'readnone' deduced for its SCC.
; CHECK: Function Attrs: noinline nosync nounwind readnone
; CHECK: Function Attrs: nofree noinline nosync nounwind readnone
; CHECK-NEXT: define void @test2_h()
define void @test2_h() noinline {
entry:
@ -152,7 +152,7 @@ exit:
; form a new SCC and should use that can deduce precise function attrs.
; This function should have had 'readnone' deduced for its SCC.
; CHECK: Function Attrs: noinline nosync nounwind readnone
; CHECK: Function Attrs: nofree noinline nosync nounwind readnone
; CHECK-NEXT: define void @test4_f1()
define void @test4_f1() noinline {
entry:
@ -175,7 +175,7 @@ entry:
}
; This function should have had 'readnone' deduced for its SCC.
; CHECK: Function Attrs: noinline nosync nounwind readnone
; CHECK: Function Attrs: nofree noinline nosync nounwind readnone
; CHECK-NEXT: define void @test4_h()
define void @test4_h() noinline {
entry: