[llvm] 93e51fa - [Attributor] AAPointerInfo can model non-escaping call uses
Johannes Doerfert via llvm-commits
llvm-commits at lists.llvm.org
Wed Oct 5 07:11:32 PDT 2022
Author: Johannes Doerfert
Date: 2022-10-05T06:29:14-07:00
New Revision: 93e51fa444cc87caca00122817c64e1fcc366eeb
URL: https://github.com/llvm/llvm-project/commit/93e51fa444cc87caca00122817c64e1fcc366eeb
DIFF: https://github.com/llvm/llvm-project/commit/93e51fa444cc87caca00122817c64e1fcc366eeb.diff
LOG: [Attributor] AAPointerInfo can model non-escaping call uses
If a call base use will not capture a pointer we can approximate the
effects. This is important especially for readnone/only uses. Even
may-write uses are not too bad with reachability in place. Capturing
is the problem as we loose track of update sides.
Added:
Modified:
llvm/lib/Transforms/IPO/AttributorAttributes.cpp
llvm/test/Transforms/Attributor/heap_to_stack_gpu.ll
llvm/test/Transforms/Attributor/value-simplify-pointer-info-struct.ll
Removed:
################################################################################
diff --git a/llvm/lib/Transforms/IPO/AttributorAttributes.cpp b/llvm/lib/Transforms/IPO/AttributorAttributes.cpp
index 8744003a7b5f..642f1f16f20c 100644
--- a/llvm/lib/Transforms/IPO/AttributorAttributes.cpp
+++ b/llvm/lib/Transforms/IPO/AttributorAttributes.cpp
@@ -1530,13 +1530,35 @@ struct AAPointerInfoCallSiteArgument final : AAPointerInfoFloating {
// sense to specialize attributes for call sites arguments instead of
// redirecting requests to the callee argument.
Argument *Arg = getAssociatedArgument();
- if (!Arg)
+ if (Arg) {
+ const IRPosition &ArgPos = IRPosition::argument(*Arg);
+ auto &ArgAA =
+ A.getAAFor<AAPointerInfo>(*this, ArgPos, DepClassTy::REQUIRED);
+ if (ArgAA.getState().isValidState())
+ return translateAndAddState(A, ArgAA, 0, *cast<CallBase>(getCtxI()),
+ /* FromCallee */ true);
+ if (!Arg->getParent()->isDeclaration())
+ return indicatePessimisticFixpoint();
+ }
+
+ const auto &NoCaptureAA =
+ A.getAAFor<AANoCapture>(*this, getIRPosition(), DepClassTy::OPTIONAL);
+
+ if (!NoCaptureAA.isAssumedNoCapture())
return indicatePessimisticFixpoint();
- const IRPosition &ArgPos = IRPosition::argument(*Arg);
- auto &ArgAA =
- A.getAAFor<AAPointerInfo>(*this, ArgPos, DepClassTy::REQUIRED);
- return translateAndAddState(A, ArgAA, 0, *cast<CallBase>(getCtxI()),
- /* FromCallee */ true);
+
+ bool IsKnown = false;
+ if (AA::isAssumedReadNone(A, getIRPosition(), *this, IsKnown))
+ return ChangeStatus::UNCHANGED;
+ bool ReadOnly = AA::isAssumedReadOnly(A, getIRPosition(), *this, IsKnown);
+
+ ChangeStatus Changed = ChangeStatus::UNCHANGED;
+ handleAccess(A, *getCtxI(), getAssociatedValue(), nullptr,
+ ReadOnly ? AccessKind::AK_MAY_READ
+ : AccessKind::AK_MAY_READ_WRITE,
+ AA::OffsetAndSize::Unknown, Changed, nullptr,
+ AA::OffsetAndSize::Unknown);
+ return Changed;
}
/// See AbstractAttribute::trackStatistics()
diff --git a/llvm/test/Transforms/Attributor/heap_to_stack_gpu.ll b/llvm/test/Transforms/Attributor/heap_to_stack_gpu.ll
index 4c9022105e65..04295912d589 100644
--- a/llvm/test/Transforms/Attributor/heap_to_stack_gpu.ll
+++ b/llvm/test/Transforms/Attributor/heap_to_stack_gpu.ll
@@ -350,6 +350,7 @@ define void @test11() {
; TEST 12
define i32 @irreducible_cfg(i32 %0) {
+;
; CHECK-LABEL: define {{[^@]+}}@irreducible_cfg
; CHECK-SAME: (i32 [[TMP0:%.*]]) {
; CHECK-NEXT: [[TMP2:%.*]] = call noalias i8* @malloc(i64 noundef 4)
diff --git a/llvm/test/Transforms/Attributor/value-simplify-pointer-info-struct.ll b/llvm/test/Transforms/Attributor/value-simplify-pointer-info-struct.ll
index 57c0ac8b85ad..988c3be5b462 100644
--- a/llvm/test/Transforms/Attributor/value-simplify-pointer-info-struct.ll
+++ b/llvm/test/Transforms/Attributor/value-simplify-pointer-info-struct.ll
@@ -29,13 +29,15 @@ target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16
;
@GlobalS = internal constant %struct.S { i32 42, double 3.140000e+00, ptr null }, align 8
+declare void @harmless_use(ptr nocapture readonly) nofree norecurse nosync nounwind readnone willreturn nocallback
+
;.
; CHECK: @[[GLOBALS:[a-zA-Z0-9_$"\\.-]+]] = internal constant [[STRUCT_S:%.*]] { i32 42, double 3.140000e+00, ptr null }, align 8
;.
define i32 @testOneFieldGlobalS() {
; CHECK: Function Attrs: nofree norecurse nosync nounwind readnone willreturn
; CHECK-LABEL: define {{[^@]+}}@testOneFieldGlobalS
-; CHECK-SAME: () #[[ATTR0:[0-9]+]] {
+; CHECK-SAME: () #[[ATTR1:[0-9]+]] {
; CHECK-NEXT: entry:
; CHECK-NEXT: br label [[IF_END:%.*]]
; CHECK: if.then:
@@ -54,6 +56,7 @@ define i32 @testOneFieldGlobalS() {
;
entry:
%i = load i32, ptr @GlobalS, align 8
+ call void @harmless_use(ptr @GlobalS)
%cmp = icmp ne i32 %i, 42
br i1 %cmp, label %if.then, label %if.end
@@ -89,7 +92,7 @@ if.end7: ; preds = %if.then5, %if.end4
define i32 @testOneFieldGlobalS_type_mismatch() {
; CHECK: Function Attrs: nofree norecurse nosync nounwind readnone willreturn
; CHECK-LABEL: define {{[^@]+}}@testOneFieldGlobalS_type_mismatch
-; CHECK-SAME: () #[[ATTR0]] {
+; CHECK-SAME: () #[[ATTR1]] {
; CHECK-NEXT: entry:
; CHECK-NEXT: [[I:%.*]] = load double, ptr @GlobalS, align 8
; CHECK-NEXT: [[IC:%.*]] = fptosi double [[I]] to i32
@@ -155,7 +158,7 @@ if.end7: ; preds = %if.then5, %if.end4
define i32 @testOneFieldGlobalS_byte_offset_wrong() {
; CHECK: Function Attrs: nofree norecurse nosync nounwind readnone willreturn
; CHECK-LABEL: define {{[^@]+}}@testOneFieldGlobalS_byte_offset_wrong
-; CHECK-SAME: () #[[ATTR0]] {
+; CHECK-SAME: () #[[ATTR1]] {
; CHECK-NEXT: entry:
; CHECK-NEXT: [[I:%.*]] = load i32, ptr getelementptr inbounds (i32, ptr @GlobalS, i32 1), align 8
; CHECK-NEXT: [[CMP:%.*]] = icmp ne i32 [[I]], 42
@@ -217,5 +220,6 @@ if.end7: ; preds = %if.then5, %if.end4
ret i32 %r.2
}
;.
-; CHECK: attributes #[[ATTR0]] = { nofree norecurse nosync nounwind readnone willreturn }
+; CHECK: attributes #[[ATTR0:[0-9]+]] = { nocallback nofree norecurse nosync nounwind readnone willreturn }
+; CHECK: attributes #[[ATTR1]] = { nofree norecurse nosync nounwind readnone willreturn }
;.
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