https://github.com/arsenm updated
https://github.com/llvm/llvm-project/pull/133627
>From 0dacedc6435fd12b29ddd786efb90989b36c816a Mon Sep 17 00:00:00 2001
From: Matt Arsenault <matthew.arsena...@amd.com>
Date: Mon, 24 Mar 2025 14:33:36 +0700
Subject: [PATCH 1/2] llvm-reduce: Reduce with early return of arguments
Extend the instruction -> return reduction with one that inserts
return of function arguments. Not sure how useful this really is. This
has more freedom since we could insert the return anywhere in the function,
but this just inserts the return in the entry block.
---
.../reduce-values-to-return-args.ll | 77 +++++++++++++++++++
llvm/tools/llvm-reduce/DeltaPasses.def | 6 +-
.../deltas/ReduceValuesToReturn.cpp | 42 +++++++++-
.../llvm-reduce/deltas/ReduceValuesToReturn.h | 1 +
4 files changed, 122 insertions(+), 4 deletions(-)
create mode 100644 llvm/test/tools/llvm-reduce/reduce-values-to-return-args.ll
diff --git a/llvm/test/tools/llvm-reduce/reduce-values-to-return-args.ll
b/llvm/test/tools/llvm-reduce/reduce-values-to-return-args.ll
new file mode 100644
index 0000000000000..abbc643822033
--- /dev/null
+++ b/llvm/test/tools/llvm-reduce/reduce-values-to-return-args.ll
@@ -0,0 +1,77 @@
+; RUN: llvm-reduce --abort-on-invalid-reduction
--delta-passes=arguments-to-return --test FileCheck --test-arg
--check-prefixes=INTERESTING --test-arg %s --test-arg --input-file %s -o %t
+; RUN: FileCheck --check-prefixes=RESULT %s < %t
+
+
+; INTERESTING-LABEL: @move_entry_block_use_argument_to_return(i32 %arg, ptr
%ptr) {
+; INTERESTING: %arg
+
+; RESULT-LABEL: define i32 @move_entry_block_use_argument_to_return(
+; RESULT-NEXT: ret i32 %arg
+; RESULT-NEXT: }
+define void @move_entry_block_use_argument_to_return(i32 %arg, ptr %ptr) {
+ store i32 %arg, ptr %ptr
+ ret void
+}
+
+; INTERESTING-LABEL: @move_entry_block_use_argument_to_return_existing_ret(i32
%arg, ptr %ptr) {
+; INTERESTING: %arg
+
+; RESULT-LABEL: define i32
@move_entry_block_use_argument_to_return_existing_ret(
+; RESULT-NEXT: ret i32 %arg
+; RESULT-NEXT: }
+define i32 @move_entry_block_use_argument_to_return_existing_ret(i32 %arg, ptr
%ptr) {
+ store i32 %arg, ptr %ptr
+ ret i32 0
+}
+
+; INTERESTING-LABEL: @move_phi_block_use_argument_to_return(i32 %arg, ptr
%ptr0, ptr %ptr1, i1 %cond0, i1 %cond1) {
+; INTERESTING: %arg
+
+; RESULT-LABEL: define i32 @move_phi_block_use_argument_to_return(
+; RESULT-NEXT: entry:
+; RESULT-NEXT: ret i32 %arg
+define void @move_phi_block_use_argument_to_return(i32 %arg, ptr %ptr0, ptr
%ptr1, i1 %cond0, i1 %cond1) {
+entry:
+ br i1 %cond0, label %bb0, label %bb1
+
+bb0:
+ %phi = phi i32 [ %arg, %entry ], [ 123, %bb1 ]
+ store i32 %arg, ptr %ptr0
+ store i32 %phi, ptr %ptr1
+ br label %bb1
+
+bb1:
+ br i1 %cond1, label %bb0, label %bb2
+
+bb2:
+ ret void
+}
+
+; INTERESTING-LABEL: define {{.*}} @keep_second_arg(i32 %arg0, ptr %arg1) {
+; INTERESTING: %arg1
+
+; RESULT-LABEL: define ptr @keep_second_arg(
+; RESULT-NEXT: ret ptr %arg1
+; RESULT-NEXT: }
+define void @keep_second_arg(i32 %arg0, ptr %arg1) {
+ store i32 %arg0, ptr %arg1
+ ret void
+}
+
+; INTERESTING-LABEL: @multi_void_return_arg(i1 %arg0, ptr %arg1, i32 %arg2) {
+; INTERESTING: i32 %arg2
+
+; RESULT-LABEL: define i32 @multi_void_return_arg(i1 %arg0, ptr %arg1, i32
%arg2) {
+; RESULT-NEXT: entry:
+; RESULT-NEXT: ret i32 %arg2
+define void @multi_void_return_arg(i1 %arg0, ptr %arg1, i32 %arg2) {
+entry:
+ br i1 %arg0, label %bb0, label %bb1
+
+bb0:
+ store i32 %arg2, ptr %arg1
+ ret void
+
+bb1:
+ ret void
+}
diff --git a/llvm/tools/llvm-reduce/DeltaPasses.def
b/llvm/tools/llvm-reduce/DeltaPasses.def
index 421e4472006b6..3aed0ccd74b84 100644
--- a/llvm/tools/llvm-reduce/DeltaPasses.def
+++ b/llvm/tools/llvm-reduce/DeltaPasses.def
@@ -49,7 +49,11 @@ DELTA_PASS_IR("attributes", reduceAttributesDeltaPass,
"Reducing Attributes")
DELTA_PASS_IR("target-features-attr", reduceTargetFeaturesAttrDeltaPass,
"Reducing target-features")
DELTA_PASS_IR("module-data", reduceModuleDataDeltaPass, "Reducing Module Data")
DELTA_PASS_IR("opcodes", reduceOpcodesDeltaPass, "Reducing Opcodes")
-DELTA_PASS_IR("instructions-to-return", reduceInstructionsToReturnDeltaPass,
"Early return of instructions")
+
+DELTA_PASS_IR("arguments-to-return", reduceArgumentsToReturnDeltaPass,
+ "Converting arguments to function return value")
+DELTA_PASS_IR("instructions-to-return", reduceInstructionsToReturnDeltaPass,
+ "Early return of instructions")
DELTA_PASS_IR("volatile", reduceVolatileInstructionsDeltaPass, "Reducing
Volatile Instructions")
DELTA_PASS_IR("atomic-ordering", reduceAtomicOrderingDeltaPass, "Reducing
Atomic Ordering")
DELTA_PASS_IR("syncscopes", reduceAtomicSyncScopesDeltaPass, "Reducing Atomic
Sync Scopes")
diff --git a/llvm/tools/llvm-reduce/deltas/ReduceValuesToReturn.cpp
b/llvm/tools/llvm-reduce/deltas/ReduceValuesToReturn.cpp
index 870918d93e557..3a00b415b0f09 100644
--- a/llvm/tools/llvm-reduce/deltas/ReduceValuesToReturn.cpp
+++ b/llvm/tools/llvm-reduce/deltas/ReduceValuesToReturn.cpp
@@ -49,10 +49,12 @@ static void rewriteFuncWithReturnType(Function &OldF, Value
*NewRetValue) {
FunctionType::get(NewRetTy, OldFuncTy->params(), OldFuncTy->isVarArg());
LLVMContext &Ctx = OldF.getContext();
- Instruction *NewRetI = cast<Instruction>(NewRetValue);
- BasicBlock *NewRetBlock = NewRetI->getParent();
+ BasicBlock &EntryBB = OldF.getEntryBlock();
+ Instruction *NewRetI = dyn_cast<Instruction>(NewRetValue);
+ BasicBlock *NewRetBlock = NewRetI ? NewRetI->getParent() : &EntryBB;
- BasicBlock::iterator NewValIt = NewRetI->getIterator();
+ BasicBlock::iterator NewValIt =
+ NewRetI ? NewRetI->getIterator() : EntryBB.end();
// Hack up any return values in other blocks, we can't leave them as ret
void.
if (OldFuncTy->getReturnType()->isVoidTy()) {
@@ -227,6 +229,40 @@ static bool tryForwardingInstructionsToReturn(
return false;
}
+static bool tryForwardingArgumentsToReturn(
+ Function &F, Oracle &O,
+ std::vector<std::pair<Function *, Value *>> &FuncsToReplace) {
+
+ Type *RetTy = F.getReturnType();
+ BasicBlock &EntryBB = F.getEntryBlock();
+
+ for (Argument &A : F.args()) {
+ if (shouldForwardValueToReturn(EntryBB, &A, RetTy) && !O.shouldKeep()) {
+ FuncsToReplace.emplace_back(&F, &A);
+ return true;
+ }
+ }
+
+ return false;
+}
+
+void llvm::reduceArgumentsToReturnDeltaPass(Oracle &O,
+ ReducerWorkItem &WorkItem) {
+ Module &Program = WorkItem.getModule();
+
+ // We're going to chaotically hack on the other users of the function in
other
+ // functions, so we need to collect a worklist of returns to replace.
+ std::vector<std::pair<Function *, Value *>> FuncsToReplace;
+
+ for (Function &F : Program.functions()) {
+ if (!F.isDeclaration() && canUseNonVoidReturnType(F))
+ tryForwardingArgumentsToReturn(F, O, FuncsToReplace);
+ }
+
+ for (auto [F, NewRetVal] : FuncsToReplace)
+ rewriteFuncWithReturnType(*F, NewRetVal);
+}
+
void llvm::reduceInstructionsToReturnDeltaPass(Oracle &O,
ReducerWorkItem &WorkItem) {
Module &Program = WorkItem.getModule();
diff --git a/llvm/tools/llvm-reduce/deltas/ReduceValuesToReturn.h
b/llvm/tools/llvm-reduce/deltas/ReduceValuesToReturn.h
index 58279421d9aae..f6dcb9b02df5d 100644
--- a/llvm/tools/llvm-reduce/deltas/ReduceValuesToReturn.h
+++ b/llvm/tools/llvm-reduce/deltas/ReduceValuesToReturn.h
@@ -12,6 +12,7 @@
#include "Delta.h"
namespace llvm {
+void reduceArgumentsToReturnDeltaPass(Oracle &O, ReducerWorkItem &WorkItem);
void reduceInstructionsToReturnDeltaPass(Oracle &O, ReducerWorkItem &WorkItem);
} // namespace llvm
>From 562a680a0500776e630f0f3105f3321be8625c25 Mon Sep 17 00:00:00 2001
From: Matt Arsenault <matthew.arsena...@amd.com>
Date: Tue, 8 Apr 2025 12:49:57 +0700
Subject: [PATCH 2/2] test work
---
.../reduce-values-to-return-args.ll | 26 ++++++++++++++-----
1 file changed, 19 insertions(+), 7 deletions(-)
diff --git a/llvm/test/tools/llvm-reduce/reduce-values-to-return-args.ll
b/llvm/test/tools/llvm-reduce/reduce-values-to-return-args.ll
index abbc643822033..e75eb9382e584 100644
--- a/llvm/test/tools/llvm-reduce/reduce-values-to-return-args.ll
+++ b/llvm/test/tools/llvm-reduce/reduce-values-to-return-args.ll
@@ -1,26 +1,27 @@
; RUN: llvm-reduce --abort-on-invalid-reduction
--delta-passes=arguments-to-return --test FileCheck --test-arg
--check-prefixes=INTERESTING --test-arg %s --test-arg --input-file %s -o %t
; RUN: FileCheck --check-prefixes=RESULT %s < %t
+@gv = global i32 0
-; INTERESTING-LABEL: @move_entry_block_use_argument_to_return(i32 %arg, ptr
%ptr) {
-; INTERESTING: %arg
+; INTERESTING-LABEL: @move_entry_block_use_argument_to_return(i32 %arg) {
+; INTERESTING: i32 %arg
; RESULT-LABEL: define i32 @move_entry_block_use_argument_to_return(
; RESULT-NEXT: ret i32 %arg
; RESULT-NEXT: }
-define void @move_entry_block_use_argument_to_return(i32 %arg, ptr %ptr) {
- store i32 %arg, ptr %ptr
+define void @move_entry_block_use_argument_to_return(i32 %arg) {
+ store i32 %arg, ptr @gv
ret void
}
-; INTERESTING-LABEL: @move_entry_block_use_argument_to_return_existing_ret(i32
%arg, ptr %ptr) {
+; INTERESTING-LABEL: @move_entry_block_use_argument_to_return_existing_ret(i32
%arg) {
; INTERESTING: %arg
; RESULT-LABEL: define i32
@move_entry_block_use_argument_to_return_existing_ret(
; RESULT-NEXT: ret i32 %arg
; RESULT-NEXT: }
-define i32 @move_entry_block_use_argument_to_return_existing_ret(i32 %arg, ptr
%ptr) {
- store i32 %arg, ptr %ptr
+define i32 @move_entry_block_use_argument_to_return_existing_ret(i32 %arg) {
+ store i32 %arg, ptr @gv
ret i32 0
}
@@ -47,6 +48,17 @@ bb2:
ret void
}
+; INTERESTING-LABEL: define {{.*}} @keep_first_arg(i32 %arg0, ptr %arg1) {
+; INTERESTING: %arg0
+
+; RESULT-LABEL: define i32 @keep_first_arg(
+; RESULT-NEXT: ret i32 %arg0
+; RESULT-NEXT: }
+define void @keep_first_arg(i32 %arg0, ptr %arg1) {
+ store i32 %arg0, ptr %arg1
+ ret void
+}
+
; INTERESTING-LABEL: define {{.*}} @keep_second_arg(i32 %arg0, ptr %arg1) {
; INTERESTING: %arg1
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