[Attributor][NFCI] Distinguish optional and required dependences

Dependences between two abstract attributes SRC and TRG come naturally in
two flavors:
  Either (1) "some" information of SRC is *required* for TRG to derive
  information, or (2) SRC is just an *optional* way for TRG to derive
  information.

While it is not strictly necessary to distinguish these types
explicitly, it can help us to converge faster, in terms of iterations,
and also cut down the number of `AbstractAttribute::update` calls.

As far as I can tell, we only use optional dependences for liveness so
far but that might change in the future. With this change the Attributor
can be informed about the "dependence class" and it will perform
appropriate actions when an Attribute is set to an invalid state, thus
one that cannot be used by others to derive information from.

7 files changed, 8 insertions, 8 deletions

diff --git a/llvm/test/Transforms/FunctionAttrs/align.ll b/llvm/test/Transforms/FunctionAttrs/align.ll
index db1c80ee643..84333b7d9e4 100644
--- a/llvm/test/Transforms/FunctionAttrs/align.ll
+++ b/llvm/test/Transforms/FunctionAttrs/align.ll
@@ -1,5 +1,5 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt -attributor -attributor-manifest-internal -attributor-disable=false -attributor-max-iterations-verify -attributor-annotate-decl-cs -attributor-max-iterations=7 -S < %s | FileCheck %s --check-prefix=ATTRIBUTOR
+; RUN: opt -attributor -attributor-manifest-internal -attributor-disable=false -attributor-max-iterations-verify -attributor-annotate-decl-cs -attributor-max-iterations=5 -S < %s | FileCheck %s --check-prefix=ATTRIBUTOR
 
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 
diff --git a/llvm/test/Transforms/FunctionAttrs/arg_returned.ll b/llvm/test/Transforms/FunctionAttrs/arg_returned.ll
index 55347a0a611..ff0475615e5 100644
--- a/llvm/test/Transforms/FunctionAttrs/arg_returned.ll
+++ b/llvm/test/Transforms/FunctionAttrs/arg_returned.ll
@@ -1,5 +1,5 @@
 ; RUN: opt -functionattrs -S < %s | FileCheck %s --check-prefix=FNATTR
-; RUN: opt -attributor -attributor-manifest-internal -attributor-disable=false -attributor-max-iterations-verify -attributor-annotate-decl-cs -attributor-max-iterations=7 -S < %s | FileCheck %s --check-prefix=ATTRIBUTOR
+; RUN: opt -attributor -attributor-manifest-internal -attributor-disable=false -attributor-max-iterations-verify -attributor-annotate-decl-cs -attributor-max-iterations=5 -S < %s | FileCheck %s --check-prefix=ATTRIBUTOR
 ; RUN: opt -attributor -attributor-manifest-internal -attributor-disable=false -attributor-annotate-decl-cs -functionattrs -S < %s | FileCheck %s --check-prefix=BOTH
 ;
 ; Test cases specifically designed for the "returned" argument attribute.
diff --git a/llvm/test/Transforms/FunctionAttrs/internal-noalias.ll b/llvm/test/Transforms/FunctionAttrs/internal-noalias.ll
index 9a5bdbf9f6b..b97c501c373 100644
--- a/llvm/test/Transforms/FunctionAttrs/internal-noalias.ll
+++ b/llvm/test/Transforms/FunctionAttrs/internal-noalias.ll
@@ -1,4 +1,4 @@
-; RUN: opt -S -passes=attributor -aa-pipeline='basic-aa' -attributor-disable=false -attributor-max-iterations-verify -attributor-annotate-decl-cs -attributor-max-iterations=7 < %s | FileCheck %s
+; RUN: opt -S -passes=attributor -aa-pipeline='basic-aa' -attributor-disable=false -attributor-max-iterations-verify -attributor-annotate-decl-cs -attributor-max-iterations=5 < %s | FileCheck %s
 
 define dso_local i32 @visible(i32* noalias %A, i32* noalias %B) #0 {
 entry:
diff --git a/llvm/test/Transforms/FunctionAttrs/liveness.ll b/llvm/test/Transforms/FunctionAttrs/liveness.ll
index ef25a0a03cf..4fea57ff921 100644
--- a/llvm/test/Transforms/FunctionAttrs/liveness.ll
+++ b/llvm/test/Transforms/FunctionAttrs/liveness.ll
@@ -1,5 +1,5 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --function-signature --scrub-attributes
-; RUN: opt -attributor --attributor-disable=false -attributor-max-iterations-verify -attributor-annotate-decl-cs -attributor-max-iterations=6 -S < %s | FileCheck %s
+; RUN: opt -attributor --attributor-disable=false -attributor-max-iterations-verify -attributor-annotate-decl-cs -attributor-max-iterations=4 -S < %s | FileCheck %s
 ; UTC_ARGS: --turn off
 
 ; CHECK: @dead_with_blockaddress_users.l = constant [2 x i8*] [i8* inttoptr (i32 1 to i8*), i8* inttoptr (i32 1 to i8*)]
diff --git a/llvm/test/Transforms/FunctionAttrs/nofree-attributor.ll b/llvm/test/Transforms/FunctionAttrs/nofree-attributor.ll
index 375a0414027..75d812195e8 100644
--- a/llvm/test/Transforms/FunctionAttrs/nofree-attributor.ll
+++ b/llvm/test/Transforms/FunctionAttrs/nofree-attributor.ll
@@ -1,5 +1,5 @@
 ; RUN: opt -functionattrs --disable-nofree-inference=false -S < %s | FileCheck %s --check-prefix=FNATTR
-; RUN: opt -attributor --attributor-disable=false -attributor-max-iterations-verify -attributor-annotate-decl-cs -attributor-max-iterations=4 -S < %s | FileCheck %s --check-prefix=ATTRIBUTOR
+; RUN: opt -attributor --attributor-disable=false -attributor-max-iterations-verify -attributor-annotate-decl-cs -attributor-max-iterations=2 -S < %s | FileCheck %s --check-prefix=ATTRIBUTOR
 
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 
diff --git a/llvm/test/Transforms/FunctionAttrs/nonnull.ll b/llvm/test/Transforms/FunctionAttrs/nonnull.ll
index 0e45061c77f..acdda1df0ae 100644
--- a/llvm/test/Transforms/FunctionAttrs/nonnull.ll
+++ b/llvm/test/Transforms/FunctionAttrs/nonnull.ll
@@ -1,8 +1,8 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt -S -functionattrs -enable-nonnull-arg-prop %s | FileCheck %s --check-prefixes=BOTH,FNATTR,OLD
 ; RUN: opt -S -passes=function-attrs -enable-nonnull-arg-prop %s | FileCheck %s --check-prefixes=BOTH,FNATTR,OLD
-; RUN: opt -attributor --attributor-disable=false -attributor-max-iterations-verify -attributor-annotate-decl-cs -attributor-max-iterations=7 -S < %s | FileCheck %s --check-prefixes=BOTH,OLD,ATTRIBUTOR,ATTRIBUTOR_OPM
-; RUN: opt -passes=attributor --attributor-disable=false -attributor-max-iterations-verify -attributor-annotate-decl-cs -attributor-max-iterations=7 -S < %s | FileCheck %s --check-prefixes=BOTH,ATTRIBUTOR,ATTRIBUTOR_NPM
+; RUN: opt -attributor --attributor-disable=false -attributor-max-iterations-verify -attributor-annotate-decl-cs -attributor-max-iterations=5 -S < %s | FileCheck %s --check-prefixes=BOTH,OLD,ATTRIBUTOR,ATTRIBUTOR_OPM
+; RUN: opt -passes=attributor --attributor-disable=false -attributor-max-iterations-verify -attributor-annotate-decl-cs -attributor-max-iterations=5 -S < %s | FileCheck %s --check-prefixes=BOTH,ATTRIBUTOR,ATTRIBUTOR_NPM
 
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 
diff --git a/llvm/test/Transforms/FunctionAttrs/read_write_returned_arguments_scc.ll b/llvm/test/Transforms/FunctionAttrs/read_write_returned_arguments_scc.ll
index 060b2168903..5285b9dcd2a 100644
--- a/llvm/test/Transforms/FunctionAttrs/read_write_returned_arguments_scc.ll
+++ b/llvm/test/Transforms/FunctionAttrs/read_write_returned_arguments_scc.ll
@@ -1,4 +1,4 @@
-; RUN: opt -functionattrs -enable-nonnull-arg-prop -attributor -attributor-manifest-internal -attributor-disable=false -attributor-max-iterations-verify -attributor-annotate-decl-cs -attributor-max-iterations=7 -S < %s | FileCheck %s
+; RUN: opt -functionattrs -enable-nonnull-arg-prop -attributor -attributor-manifest-internal -attributor-disable=false -attributor-max-iterations-verify -attributor-annotate-decl-cs -attributor-max-iterations=6 -S < %s | FileCheck %s
 ;
 ; This is an evolved example to stress test SCC parameter attribute propagation.
 ; The SCC in this test is made up of the following six function, three of which