[polly] 2866778 - [Polly][ManualOpt] Match interpretation of unroll metadata to LoopUnrolls's.
Michael Kruse via llvm-commits
llvm-commits at lists.llvm.org
Sat Apr 24 02:31:56 PDT 2021
Author: Michael Kruse
Date: 2021-04-24T04:30:19-05:00
New Revision: 286677870b306582321dcddb1531d8860bc446db
URL: https://github.com/llvm/llvm-project/commit/286677870b306582321dcddb1531d8860bc446db
DIFF: https://github.com/llvm/llvm-project/commit/286677870b306582321dcddb1531d8860bc446db.diff
LOG: [Polly][ManualOpt] Match interpretation of unroll metadata to LoopUnrolls's.
We previously had a different interpretation of unroll transformation
attributes than how LoopUnroll interpreted it. In particular,
llvm.loop.unroll.enable was needed explicitly to enable it and disabling
metadata was ignored.
Additionally, it required that either full unrolling or an unroll factor
to be specified or fail otherwise. An unroll factor is still required,
but the transformation is ignored with the hope that LoopUnroll is going
to apply the unrolling, since Polly currently does not implement an
heuristic.
Fixes llvm.org/PR50109
Added:
polly/test/ScheduleOptimizer/ManualOptimization/unroll_disable.ll
polly/test/ScheduleOptimizer/ManualOptimization/unroll_heuristic.ll
Modified:
polly/include/polly/Support/ScopHelper.h
polly/lib/Support/ScopHelper.cpp
polly/lib/Transform/ManualOptimizer.cpp
polly/test/ScheduleOptimizer/ManualOptimization/unroll_full.ll
polly/test/ScheduleOptimizer/ManualOptimization/unroll_partial.ll
Removed:
################################################################################
diff --git a/polly/include/polly/Support/ScopHelper.h b/polly/include/polly/Support/ScopHelper.h
index 6b385303293fb..b1c605549c610 100644
--- a/polly/include/polly/Support/ScopHelper.h
+++ b/polly/include/polly/Support/ScopHelper.h
@@ -562,6 +562,14 @@ bool hasDebugCall(ScopStmt *Stmt);
llvm::Optional<llvm::Metadata *> findMetadataOperand(llvm::MDNode *LoopMD,
llvm::StringRef Name);
+/// Find a boolean property value in a LoopID. The value not being defined is
+/// interpreted as a false value.
+bool getBooleanLoopAttribute(llvm::MDNode *LoopID, llvm::StringRef Name);
+
+/// Find an integers property value in a LoopID.
+llvm::Optional<int> getOptionalIntLoopAttribute(llvm::MDNode *LoopID,
+ llvm::StringRef Name);
+
/// Does the loop's LoopID contain a 'llvm.loop.disable_heuristics' property?
///
/// This is equivalent to llvm::hasDisableAllTransformsHint(Loop*), but
@@ -569,6 +577,7 @@ llvm::Optional<llvm::Metadata *> findMetadataOperand(llvm::MDNode *LoopMD,
/// which clashes with polly::MemoryAccess. Declaring this alias here avoid
/// having to include LoopUtils.h in other files.
bool hasDisableAllTransformsHint(llvm::Loop *L);
+bool hasDisableAllTransformsHint(llvm::MDNode *LoopID);
/// Represent the attributes of a loop.
struct BandAttr {
diff --git a/polly/lib/Support/ScopHelper.cpp b/polly/lib/Support/ScopHelper.cpp
index d4a2bfc8d1aab..efb3b9afa6980 100644
--- a/polly/lib/Support/ScopHelper.cpp
+++ b/polly/lib/Support/ScopHelper.cpp
@@ -746,6 +746,21 @@ static MDNode *findNamedMetadataNode(MDNode *LoopMD, StringRef Name) {
return nullptr;
}
+static Optional<const MDOperand *> findNamedMetadataArg(MDNode *LoopID,
+ StringRef Name) {
+ MDNode *MD = findNamedMetadataNode(LoopID, Name);
+ if (!MD)
+ return None;
+ switch (MD->getNumOperands()) {
+ case 1:
+ return nullptr;
+ case 2:
+ return &MD->getOperand(1);
+ default:
+ llvm_unreachable("loop metadata has 0 or 1 operand");
+ }
+}
+
Optional<Metadata *> polly::findMetadataOperand(MDNode *LoopMD,
StringRef Name) {
MDNode *MD = findNamedMetadataNode(LoopMD, Name);
@@ -761,10 +776,49 @@ Optional<Metadata *> polly::findMetadataOperand(MDNode *LoopMD,
}
}
+static Optional<bool> getOptionalBoolLoopAttribute(MDNode *LoopID,
+ StringRef Name) {
+ MDNode *MD = findNamedMetadataNode(LoopID, Name);
+ if (!MD)
+ return None;
+ switch (MD->getNumOperands()) {
+ case 1:
+ return true;
+ case 2:
+ if (ConstantInt *IntMD =
+ mdconst::extract_or_null<ConstantInt>(MD->getOperand(1).get()))
+ return IntMD->getZExtValue();
+ return true;
+ }
+ llvm_unreachable("unexpected number of options");
+}
+
+bool polly::getBooleanLoopAttribute(MDNode *LoopID, StringRef Name) {
+ return getOptionalBoolLoopAttribute(LoopID, Name).getValueOr(false);
+}
+
+llvm::Optional<int> polly::getOptionalIntLoopAttribute(MDNode *LoopID,
+ StringRef Name) {
+ const MDOperand *AttrMD =
+ findNamedMetadataArg(LoopID, Name).getValueOr(nullptr);
+ if (!AttrMD)
+ return None;
+
+ ConstantInt *IntMD = mdconst::extract_or_null<ConstantInt>(AttrMD->get());
+ if (!IntMD)
+ return None;
+
+ return IntMD->getSExtValue();
+}
+
bool polly::hasDisableAllTransformsHint(Loop *L) {
return llvm::hasDisableAllTransformsHint(L);
}
+bool polly::hasDisableAllTransformsHint(llvm::MDNode *LoopID) {
+ return getBooleanLoopAttribute(LoopID, "llvm.loop.disable_nonforced");
+}
+
isl::id polly::getIslLoopAttr(isl::ctx Ctx, BandAttr *Attr) {
assert(Attr && "Must be a valid BandAttr");
diff --git a/polly/lib/Transform/ManualOptimizer.cpp b/polly/lib/Transform/ManualOptimizer.cpp
index ced70cc32d514..91f309eb6fd35 100644
--- a/polly/lib/Transform/ManualOptimizer.cpp
+++ b/polly/lib/Transform/ManualOptimizer.cpp
@@ -17,6 +17,7 @@
#include "llvm/ADT/StringRef.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/IR/Metadata.h"
+#include "llvm/Transforms/Utils/LoopUtils.h"
#define DEBUG_TYPE "polly-opt-manual"
@@ -24,42 +25,36 @@ using namespace polly;
using namespace llvm;
namespace {
-/// Extract an integer property from an LoopID metadata node.
-static llvm::Optional<int64_t> findOptionalIntOperand(MDNode *LoopMD,
- StringRef Name) {
- Metadata *AttrMD = findMetadataOperand(LoopMD, Name).getValueOr(nullptr);
- if (!AttrMD)
- return None;
-
- ConstantInt *IntMD = mdconst::extract_or_null<ConstantInt>(AttrMD);
- if (!IntMD)
- return None;
-
- return IntMD->getSExtValue();
-}
+/// Same as llvm::hasUnrollTransformation(), but takes a LoopID as argument
+/// instead of a Loop.
+static TransformationMode hasUnrollTransformation(MDNode *LoopID) {
+ if (getBooleanLoopAttribute(LoopID, "llvm.loop.unroll.disable"))
+ return TM_SuppressedByUser;
-/// Extract boolean property from an LoopID metadata node.
-static llvm::Optional<bool> findOptionalBoolOperand(MDNode *LoopMD,
- StringRef Name) {
- auto MD = findOptionMDForLoopID(LoopMD, Name);
- if (!MD)
- return None;
-
- switch (MD->getNumOperands()) {
- case 1:
- // When the value is absent it is interpreted as 'attribute set'.
- return true;
- case 2:
- ConstantInt *IntMD =
- mdconst::extract_or_null<ConstantInt>(MD->getOperand(1).get());
- return IntMD->getZExtValue() != 0;
- }
- llvm_unreachable("unexpected number of options");
+ Optional<int> Count =
+ getOptionalIntLoopAttribute(LoopID, "llvm.loop.unroll.count");
+ if (Count.hasValue())
+ return Count.getValue() == 1 ? TM_SuppressedByUser : TM_ForcedByUser;
+
+ if (getBooleanLoopAttribute(LoopID, "llvm.loop.unroll.enable"))
+ return TM_ForcedByUser;
+
+ if (getBooleanLoopAttribute(LoopID, "llvm.loop.unroll.full"))
+ return TM_ForcedByUser;
+
+ if (hasDisableAllTransformsHint(LoopID))
+ return TM_Disable;
+
+ return TM_Unspecified;
}
/// Apply full or partial unrolling.
static isl::schedule applyLoopUnroll(MDNode *LoopMD,
isl::schedule_node BandToUnroll) {
+ TransformationMode UnrollMode = ::hasUnrollTransformation(LoopMD);
+ if (UnrollMode & TM_Disable)
+ return {};
+
assert(BandToUnroll);
// TODO: Isl's codegen also supports unrolling by isl_ast_build via
// isl_schedule_node_band_set_ast_build_options({ unroll[x] }) which would be
@@ -67,10 +62,9 @@ static isl::schedule applyLoopUnroll(MDNode *LoopMD,
// unrolled loop could be input of another loop transformation which expects
// the explicit schedule nodes. That is, we would need this explicit expansion
// anyway and using the ISL codegen option is a compile-time optimization.
- int64_t Factor =
- findOptionalIntOperand(LoopMD, "llvm.loop.unroll.count").getValueOr(0);
- bool Full = findOptionalBoolOperand(LoopMD, "llvm.loop.unroll.full")
- .getValueOr(false);
+ int64_t Factor = getOptionalIntLoopAttribute(LoopMD, "llvm.loop.unroll.count")
+ .getValueOr(0);
+ bool Full = getBooleanLoopAttribute(LoopMD, "llvm.loop.unroll.full");
assert((!Full || !(Factor > 0)) &&
"Cannot unroll fully and partially at the same time");
@@ -80,7 +74,8 @@ static isl::schedule applyLoopUnroll(MDNode *LoopMD,
if (Factor > 0)
return applyPartialUnroll(BandToUnroll, Factor);
- llvm_unreachable("Negative unroll factor");
+ // For heuristic unrolling, fall back to LLVM's LoopUnroll pass.
+ return {};
}
// Return the properties from a LoopID. Scalar properties are ignored.
@@ -143,16 +138,18 @@ class SearchTransformVisitor
continue;
StringRef AttrName = NameMD->getString();
- if (AttrName == "llvm.loop.unroll.enable") {
- // TODO: Handle disabling like llvm::hasUnrollTransformation().
+ // Honor transformation order; transform the first transformation in the
+ // list first.
+ if (AttrName == "llvm.loop.unroll.enable" ||
+ AttrName == "llvm.loop.unroll.count" ||
+ AttrName == "llvm.loop.unroll.full") {
Result = applyLoopUnroll(LoopMD, Band);
- } else {
- // not a loop transformation; look for next property
- continue;
+ if (Result)
+ return;
}
- assert(Result && "expecting applied transformation");
- return;
+ // not a loop transformation; look for next property
+ continue;
}
}
diff --git a/polly/test/ScheduleOptimizer/ManualOptimization/unroll_disable.ll b/polly/test/ScheduleOptimizer/ManualOptimization/unroll_disable.ll
new file mode 100644
index 0000000000000..3e8521198aa34
--- /dev/null
+++ b/polly/test/ScheduleOptimizer/ManualOptimization/unroll_disable.ll
@@ -0,0 +1,37 @@
+; RUN: opt %loadPolly -polly-opt-isl -polly-pragma-based-opts=1 -analyze < %s | FileCheck %s --match-full-lines
+;
+; Override unroll metadata with llvm.loop.unroll.disable.
+;
+define void @func(i32 %n, double* noalias nonnull %A) {
+entry:
+ br label %for
+
+for:
+ %j = phi i32 [0, %entry], [%j.inc, %inc]
+ %j.cmp = icmp slt i32 %j, %n
+ br i1 %j.cmp, label %body, label %exit
+
+ body:
+ store double 42.0, double* %A
+ br label %inc
+
+inc:
+ %j.inc = add nuw nsw i32 %j, 1
+ br label %for, !llvm.loop !2
+
+exit:
+ br label %return
+
+return:
+ ret void
+}
+
+
+!2 = distinct !{!2, !3, !4}
+!3 = !{!"llvm.loop.unroll.count", i32 4}
+!4 = !{!"llvm.loop.unroll.disable"}
+
+
+; CHECK-LABEL: Printing analysis 'Polly - Optimize schedule of SCoP' for region: 'for => return' in function 'func':
+; CHECK-NEXT: Calculated schedule:
+; CHECK-NEXT: n/a
diff --git a/polly/test/ScheduleOptimizer/ManualOptimization/unroll_full.ll b/polly/test/ScheduleOptimizer/ManualOptimization/unroll_full.ll
index 55c9ebf05b9ad..833ea50e62e7d 100644
--- a/polly/test/ScheduleOptimizer/ManualOptimization/unroll_full.ll
+++ b/polly/test/ScheduleOptimizer/ManualOptimization/unroll_full.ll
@@ -27,8 +27,7 @@ return:
}
-!2 = distinct !{!2, !4, !5}
-!4 = !{!"llvm.loop.unroll.enable", i1 true}
+!2 = distinct !{!2, !5}
!5 = !{!"llvm.loop.unroll.full"}
diff --git a/polly/test/ScheduleOptimizer/ManualOptimization/unroll_heuristic.ll b/polly/test/ScheduleOptimizer/ManualOptimization/unroll_heuristic.ll
new file mode 100644
index 0000000000000..ea471600440ca
--- /dev/null
+++ b/polly/test/ScheduleOptimizer/ManualOptimization/unroll_heuristic.ll
@@ -0,0 +1,38 @@
+; RUN: opt %loadPolly -polly-opt-isl -polly-pragma-based-opts=1 -analyze < %s | FileCheck %s --match-full-lines
+; RUN: opt %loadPolly -polly-opt-isl -polly-pragma-based-opts=0 -analyze < %s | FileCheck %s --match-full-lines
+;
+; Unrolling with heuristic factor.
+; Currently not supported and expected to be handled by LLVM's unroll pass.
+;
+define void @func(i32 %n, double* noalias nonnull %A) {
+entry:
+ br label %for
+
+for:
+ %j = phi i32 [0, %entry], [%j.inc, %inc]
+ %j.cmp = icmp slt i32 %j, %n
+ br i1 %j.cmp, label %body, label %exit
+
+ body:
+ store double 42.0, double* %A
+ br label %inc
+
+inc:
+ %j.inc = add nuw nsw i32 %j, 1
+ br label %for, !llvm.loop !2
+
+exit:
+ br label %return
+
+return:
+ ret void
+}
+
+
+!2 = distinct !{!2, !4}
+!4 = !{!"llvm.loop.unroll.enable", i1 true}
+
+
+; CHECK-LABEL: Printing analysis 'Polly - Optimize schedule of SCoP' for region: 'for => return' in function 'func':
+; CHECK-NEXT: Calculated schedule:
+; CHECK-NEXT: n/a
diff --git a/polly/test/ScheduleOptimizer/ManualOptimization/unroll_partial.ll b/polly/test/ScheduleOptimizer/ManualOptimization/unroll_partial.ll
index 4fd3816b2d816..4e17c9ec121a2 100644
--- a/polly/test/ScheduleOptimizer/ManualOptimization/unroll_partial.ll
+++ b/polly/test/ScheduleOptimizer/ManualOptimization/unroll_partial.ll
@@ -28,8 +28,7 @@ return:
}
-!2 = distinct !{!2, !4, !5}
-!4 = !{!"llvm.loop.unroll.enable", i1 true}
+!2 = distinct !{!2, !5}
!5 = !{!"llvm.loop.unroll.count", i4 4}
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