[llvm] [DFAJumpThreading] Add MaxOuterUseBlocks threshold (PR #163428)
Hongyu Chen via llvm-commits
llvm-commits at lists.llvm.org
Wed Oct 29 08:07:04 PDT 2025
https://github.com/XChy updated https://github.com/llvm/llvm-project/pull/163428
>From 2c9d30def6b0f13614c8984a0da346dac3c69c00 Mon Sep 17 00:00:00 2001
From: XChy <xxs_chy at outlook.com>
Date: Wed, 15 Oct 2025 01:30:40 +0800
Subject: [PATCH 1/3] [DFAJumpThreading] Add MaxOuterUseBlocks threshold
---
.../Transforms/Scalar/DFAJumpThreading.cpp | 38 ++++++++++++++++---
1 file changed, 33 insertions(+), 5 deletions(-)
diff --git a/llvm/lib/Transforms/Scalar/DFAJumpThreading.cpp b/llvm/lib/Transforms/Scalar/DFAJumpThreading.cpp
index 66e45ecbde7df..e84ca819b93d8 100644
--- a/llvm/lib/Transforms/Scalar/DFAJumpThreading.cpp
+++ b/llvm/lib/Transforms/Scalar/DFAJumpThreading.cpp
@@ -122,16 +122,22 @@ static cl::opt<unsigned>
cl::desc("Maximum cost accepted for the transformation"),
cl::Hidden, cl::init(50));
-extern cl::opt<bool> ProfcheckDisableMetadataFixes;
-
-} // namespace llvm
-
static cl::opt<double> MaxClonedRate(
"dfa-max-cloned-rate",
cl::desc(
"Maximum cloned instructions rate accepted for the transformation"),
cl::Hidden, cl::init(7.5));
+static cl::opt<unsigned>
+ MaxOuterUseBlocks("dfa-max-out-use-blocks",
+ cl::desc("Maximum unduplicated blocks with outer uses "
+ "accepted for the transformation"),
+ cl::Hidden, cl::init(40));
+
+extern cl::opt<bool> ProfcheckDisableMetadataFixes;
+
+} // namespace llvm
+
namespace {
class SelectInstToUnfold {
SelectInst *SI;
@@ -965,8 +971,16 @@ struct TransformDFA {
// SLPVectorizer.
// TODO: Thread the switch partially before reaching the threshold.
uint64_t NumOrigInst = 0;
- for (auto *BB : DuplicateMap.keys())
+ uint64_t NumOuterUseBlock = 0;
+ for (auto *BB : DuplicateMap.keys()) {
NumOrigInst += BB->sizeWithoutDebug();
+ // Only unduplicated blocks with single predecessor require new phi
+ // nodes.
+ for (auto *Succ : successors(BB))
+ if (!DuplicateMap.count(Succ) && Succ->getSinglePredecessor())
+ NumOuterUseBlock++;
+ }
+
if (double(NumClonedInst) / double(NumOrigInst) > MaxClonedRate) {
LLVM_DEBUG(dbgs() << "DFA Jump Threading: Not jump threading, too much "
"instructions wll be cloned\n");
@@ -977,6 +991,20 @@ struct TransformDFA {
return false;
}
+ // Too much unduplicated blocks with outer uses may cause too much
+ // insertions of phi nodes for duplicated definitions. TODO: Drop this
+ // threshold if we come up with another way to reduce the number of inserted
+ // phi nodes.
+ if (NumOuterUseBlock > MaxOuterUseBlocks) {
+ LLVM_DEBUG(dbgs() << "DFA Jump Threading: Not jump threading, too much "
+ "blocks with outer uses\n");
+ ORE->emit([&]() {
+ return OptimizationRemarkMissed(DEBUG_TYPE, "NotProfitable", Switch)
+ << "Too much blocks with outer uses.";
+ });
+ return false;
+ }
+
InstructionCost DuplicationCost = 0;
unsigned JumpTableSize = 0;
>From c23bc4b9004c5b76ddbadf688b1b3bfa532e36c7 Mon Sep 17 00:00:00 2001
From: XChy <xxs_chy at outlook.com>
Date: Wed, 29 Oct 2025 00:22:04 +0800
Subject: [PATCH 2/3] Add test coverage
---
.../DFAJumpThreading/max-outer-uses.ll | 253 ++++++++++++++++++
1 file changed, 253 insertions(+)
create mode 100644 llvm/test/Transforms/DFAJumpThreading/max-outer-uses.ll
diff --git a/llvm/test/Transforms/DFAJumpThreading/max-outer-uses.ll b/llvm/test/Transforms/DFAJumpThreading/max-outer-uses.ll
new file mode 100644
index 0000000000000..f059754b8221c
--- /dev/null
+++ b/llvm/test/Transforms/DFAJumpThreading/max-outer-uses.ll
@@ -0,0 +1,253 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 6
+; RUN: opt -S -passes=dfa-jump-threading -dfa-max-out-use-blocks=5 %s | FileCheck %s
+
+define void @max_outer_uses_by_switch(i32 %cond) {
+; CHECK-LABEL: define void @max_outer_uses_by_switch(
+; CHECK-SAME: i32 [[COND:%.*]]) {
+; CHECK-NEXT: [[ENTRY:.*]]:
+; CHECK-NEXT: br label %[[SWITCH_BB:.*]]
+; CHECK: [[SWITCH_BB]]:
+; CHECK-NEXT: [[PHI:%.*]] = phi i32 [ 0, %[[ENTRY]] ], [ [[ONE:%.*]], %[[CASE1_SUCC:.*]] ], [ 2, %[[CASE2:.*]] ]
+; CHECK-NEXT: switch i32 [[PHI]], label %[[DEFAULT_DEST:.*]] [
+; CHECK-NEXT: i32 0, label %[[CASE1:.*]]
+; CHECK-NEXT: i32 1, label %[[CASE2]]
+; CHECK-NEXT: ]
+; CHECK: [[CASE1]]:
+; CHECK-NEXT: br label %[[CASE1_SUCC]]
+; CHECK: [[CASE1_SUCC]]:
+; CHECK-NEXT: [[ONE]] = phi i32 [ 1, %[[CASE1]] ]
+; CHECK-NEXT: switch i32 [[COND]], label %[[SWITCH_BB]] [
+; CHECK-NEXT: i32 0, label %[[OUTER1:.*]]
+; CHECK-NEXT: i32 1, label %[[OUTER2:.*]]
+; CHECK-NEXT: i32 2, label %[[OUTER3:.*]]
+; CHECK-NEXT: i32 3, label %[[OUTER4:.*]]
+; CHECK-NEXT: ]
+; CHECK: [[CASE2]]:
+; CHECK-NEXT: br label %[[SWITCH_BB]]
+; CHECK: [[OUTER1]]:
+; CHECK-NEXT: ret void
+; CHECK: [[OUTER2]]:
+; CHECK-NEXT: ret void
+; CHECK: [[OUTER3]]:
+; CHECK-NEXT: ret void
+; CHECK: [[OUTER4]]:
+; CHECK-NEXT: ret void
+; CHECK: [[DEFAULT_DEST]]:
+; CHECK-NEXT: ret void
+;
+entry:
+ br label %switch_bb
+
+switch_bb:
+ %phi = phi i32 [ 0, %entry ], [ %one, %case1_succ ], [ 2, %case2 ]
+ switch i32 %phi, label %default_dest [
+ i32 0, label %case1
+ i32 1, label %case2
+ ]
+
+case1:
+ br label %case1_succ
+
+case1_succ:
+ %one = phi i32 [ 1, %case1 ]
+ switch i32 %cond, label %switch_bb [
+ i32 0, label %outer1
+ i32 1, label %outer2
+ i32 2, label %outer3
+ i32 3, label %outer4
+ ]
+
+case2:
+ br label %switch_bb
+
+outer1:
+ ret void
+
+outer2:
+ ret void
+
+outer3:
+ ret void
+
+outer4:
+ ret void
+
+default_dest:
+ ret void
+}
+
+define void @less_outer_uses_by_switch(i32 %cond, i1 %c1) {
+; CHECK-LABEL: define void @less_outer_uses_by_switch(
+; CHECK-SAME: i32 [[COND:%.*]], i1 [[C1:%.*]]) {
+; CHECK-NEXT: [[ENTRY:.*]]:
+; CHECK-NEXT: br label %[[SWITCH_BB:.*]]
+; CHECK: [[SWITCH_BB]]:
+; CHECK-NEXT: [[PHI:%.*]] = phi i32 [ 0, %[[ENTRY]] ], [ poison, %[[CASE1_SUCC:.*]] ]
+; CHECK-NEXT: switch i32 [[PHI]], label %[[DEFAULT_DEST:.*]] [
+; CHECK-NEXT: i32 0, label %[[CASE1:.*]]
+; CHECK-NEXT: i32 1, label %[[CASE2:.*]]
+; CHECK-NEXT: ]
+; CHECK: [[SWITCH_BB_JT2:.*]]:
+; CHECK-NEXT: [[PHI_JT2:%.*]] = phi i32 [ 2, %[[CASE2]] ]
+; CHECK-NEXT: br label %[[DEFAULT_DEST]]
+; CHECK: [[SWITCH_BB_JT1:.*]]:
+; CHECK-NEXT: [[PHI_JT1:%.*]] = phi i32 [ [[ONE_JT1:%.*]], %[[CASE1_SUCC_JT1:.*]] ]
+; CHECK-NEXT: br label %[[CASE2]]
+; CHECK: [[CASE1]]:
+; CHECK-NEXT: br label %[[CASE1_SUCC_JT1]]
+; CHECK: [[CASE1_SUCC]]:
+; CHECK-NEXT: switch i32 [[COND]], label %[[SWITCH_BB]] [
+; CHECK-NEXT: i32 0, label %[[OUTER1:.*]]
+; CHECK-NEXT: i32 1, label %[[OUTER2:.*]]
+; CHECK-NEXT: ]
+; CHECK: [[CASE1_SUCC_JT1]]:
+; CHECK-NEXT: [[ONE_JT1]] = phi i32 [ 1, %[[CASE1]] ]
+; CHECK-NEXT: switch i32 [[COND]], label %[[SWITCH_BB_JT1]] [
+; CHECK-NEXT: i32 0, label %[[OUTER1]]
+; CHECK-NEXT: i32 1, label %[[OUTER2]]
+; CHECK-NEXT: ]
+; CHECK: [[CASE2]]:
+; CHECK-NEXT: br label %[[SWITCH_BB_JT2]]
+; CHECK: [[OUTER1]]:
+; CHECK-NEXT: ret void
+; CHECK: [[OUTER2]]:
+; CHECK-NEXT: ret void
+; CHECK: [[DEFAULT_DEST]]:
+; CHECK-NEXT: ret void
+;
+entry:
+ br label %switch_bb
+
+switch_bb:
+ %phi = phi i32 [ 0, %entry ], [ %one, %case1_succ ], [ 2, %case2 ]
+ switch i32 %phi, label %default_dest [
+ i32 0, label %case1
+ i32 1, label %case2
+ ]
+
+case1:
+ br label %case1_succ
+
+case1_succ:
+ %one = phi i32 [ 1, %case1 ]
+ switch i32 %cond, label %switch_bb [
+ i32 0, label %outer1
+ i32 1, label %outer2
+ ]
+
+case2:
+ br label %switch_bb
+
+outer1:
+ ret void
+
+outer2:
+ ret void
+
+default_dest:
+ ret void
+}
+
+
+define void @max_outer_uses_multi_preds(i32 %cond) {
+; CHECK-LABEL: define void @max_outer_uses_multi_preds(
+; CHECK-SAME: i32 [[COND:%.*]]) {
+; CHECK-NEXT: [[ENTRY:.*]]:
+; CHECK-NEXT: br label %[[SWITCH_BB:.*]]
+; CHECK: [[SWITCH_BB]]:
+; CHECK-NEXT: [[PHI:%.*]] = phi i32 [ 0, %[[ENTRY]] ], [ poison, %[[CASE1_SUCC:.*]] ]
+; CHECK-NEXT: switch i32 [[PHI]], label %[[DEFAULT_DEST:.*]] [
+; CHECK-NEXT: i32 0, label %[[CASE1:.*]]
+; CHECK-NEXT: i32 1, label %[[CASE2:.*]]
+; CHECK-NEXT: i32 2, label %[[CASE3:.*]]
+; CHECK-NEXT: ]
+; CHECK: [[SWITCH_BB_JT2:.*]]:
+; CHECK-NEXT: [[PHI_JT2:%.*]] = phi i32 [ 2, %[[CASE2]] ]
+; CHECK-NEXT: br label %[[CASE3]]
+; CHECK: [[SWITCH_BB_JT1:.*]]:
+; CHECK-NEXT: [[PHI_JT1:%.*]] = phi i32 [ [[ONE_JT1:%.*]], %[[CASE1_SUCC_JT1:.*]] ]
+; CHECK-NEXT: br label %[[CASE2]]
+; CHECK: [[CASE1]]:
+; CHECK-NEXT: br label %[[CASE1_SUCC_JT1]]
+; CHECK: [[CASE1_SUCC]]:
+; CHECK-NEXT: switch i32 [[COND]], label %[[SWITCH_BB]] [
+; CHECK-NEXT: i32 0, label %[[OUTER1:.*]]
+; CHECK-NEXT: i32 1, label %[[OUTER2:.*]]
+; CHECK-NEXT: i32 2, label %[[OUTER3:.*]]
+; CHECK-NEXT: i32 3, label %[[OUTER4:.*]]
+; CHECK-NEXT: ]
+; CHECK: [[CASE1_SUCC_JT1]]:
+; CHECK-NEXT: [[ONE_JT1]] = phi i32 [ 1, %[[CASE1]] ]
+; CHECK-NEXT: switch i32 [[COND]], label %[[SWITCH_BB_JT1]] [
+; CHECK-NEXT: i32 0, label %[[OUTER1]]
+; CHECK-NEXT: i32 1, label %[[OUTER2]]
+; CHECK-NEXT: i32 2, label %[[OUTER3]]
+; CHECK-NEXT: i32 3, label %[[OUTER4]]
+; CHECK-NEXT: ]
+; CHECK: [[CASE2]]:
+; CHECK-NEXT: br label %[[SWITCH_BB_JT2]]
+; CHECK: [[CASE3]]:
+; CHECK-NEXT: switch i32 [[COND]], label %[[OUTER4]] [
+; CHECK-NEXT: i32 0, label %[[OUTER1]]
+; CHECK-NEXT: i32 1, label %[[OUTER2]]
+; CHECK-NEXT: i32 2, label %[[OUTER3]]
+; CHECK-NEXT: ]
+; CHECK: [[OUTER1]]:
+; CHECK-NEXT: ret void
+; CHECK: [[OUTER2]]:
+; CHECK-NEXT: ret void
+; CHECK: [[OUTER3]]:
+; CHECK-NEXT: ret void
+; CHECK: [[OUTER4]]:
+; CHECK-NEXT: ret void
+; CHECK: [[DEFAULT_DEST]]:
+; CHECK-NEXT: ret void
+;
+entry:
+ br label %switch_bb
+
+switch_bb:
+ %phi = phi i32 [ 0, %entry ], [ %one, %case1_succ ], [ 2, %case2 ]
+ switch i32 %phi, label %default_dest [
+ i32 0, label %case1
+ i32 1, label %case2
+ i32 2, label %case3
+ ]
+
+case1:
+ br label %case1_succ
+
+case1_succ:
+ %one = phi i32 [ 1, %case1 ]
+ switch i32 %cond, label %switch_bb [
+ i32 0, label %outer1
+ i32 1, label %outer2
+ i32 2, label %outer3
+ i32 3, label %outer4
+ ]
+
+case2:
+ br label %switch_bb
+
+case3:
+ switch i32 %cond, label %outer4 [
+ i32 0, label %outer1
+ i32 1, label %outer2
+ i32 2, label %outer3
+ ]
+
+outer1:
+ ret void
+
+outer2:
+ ret void
+
+outer3:
+ ret void
+
+outer4:
+ ret void
+
+default_dest:
+ ret void
+}
>From 476c78e1a8693bac1a8eadfc02245f8a14df00db Mon Sep 17 00:00:00 2001
From: XChy <xxs_chy at outlook.com>
Date: Wed, 29 Oct 2025 23:06:49 +0800
Subject: [PATCH 3/3] Improve tests
---
.../DFAJumpThreading/max-outer-uses.ll | 171 +++++++++++++-----
1 file changed, 122 insertions(+), 49 deletions(-)
diff --git a/llvm/test/Transforms/DFAJumpThreading/max-outer-uses.ll b/llvm/test/Transforms/DFAJumpThreading/max-outer-uses.ll
index f059754b8221c..dfcc5b1a5c3fe 100644
--- a/llvm/test/Transforms/DFAJumpThreading/max-outer-uses.ll
+++ b/llvm/test/Transforms/DFAJumpThreading/max-outer-uses.ll
@@ -1,21 +1,27 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 6
; RUN: opt -S -passes=dfa-jump-threading -dfa-max-out-use-blocks=5 %s | FileCheck %s
-define void @max_outer_uses_by_switch(i32 %cond) {
+declare void @use(i32)
+
+define void @max_outer_uses_by_switch(i32 %cond, ptr %p) {
; CHECK-LABEL: define void @max_outer_uses_by_switch(
-; CHECK-SAME: i32 [[COND:%.*]]) {
+; CHECK-SAME: i32 [[COND:%.*]], ptr [[P:%.*]]) {
; CHECK-NEXT: [[ENTRY:.*]]:
; CHECK-NEXT: br label %[[SWITCH_BB:.*]]
; CHECK: [[SWITCH_BB]]:
-; CHECK-NEXT: [[PHI:%.*]] = phi i32 [ 0, %[[ENTRY]] ], [ [[ONE:%.*]], %[[CASE1_SUCC:.*]] ], [ 2, %[[CASE2:.*]] ]
+; CHECK-NEXT: [[PHI:%.*]] = phi i32 [ 0, %[[ENTRY]] ], [ [[DETERMINE:%.*]], %[[SUB_SWITCH_BB:.*]] ], [ 2, %[[CASE2:.*]] ]
; CHECK-NEXT: switch i32 [[PHI]], label %[[DEFAULT_DEST:.*]] [
; CHECK-NEXT: i32 0, label %[[CASE1:.*]]
; CHECK-NEXT: i32 1, label %[[CASE2]]
+; CHECK-NEXT: i32 2, label %[[CASE3:.*]]
; CHECK-NEXT: ]
; CHECK: [[CASE1]]:
-; CHECK-NEXT: br label %[[CASE1_SUCC]]
-; CHECK: [[CASE1_SUCC]]:
-; CHECK-NEXT: [[ONE]] = phi i32 [ 1, %[[CASE1]] ]
+; CHECK-NEXT: br label %[[SUB_SWITCH_BB]]
+; CHECK: [[CASE3]]:
+; CHECK-NEXT: br label %[[SUB_SWITCH_BB]]
+; CHECK: [[SUB_SWITCH_BB]]:
+; CHECK-NEXT: [[DETERMINE]] = phi i32 [ 1, %[[CASE1]] ], [ 3, %[[CASE3]] ]
+; CHECK-NEXT: [[DEF:%.*]] = load i32, ptr [[P]], align 4
; CHECK-NEXT: switch i32 [[COND]], label %[[SWITCH_BB]] [
; CHECK-NEXT: i32 0, label %[[OUTER1:.*]]
; CHECK-NEXT: i32 1, label %[[OUTER2:.*]]
@@ -25,12 +31,16 @@ define void @max_outer_uses_by_switch(i32 %cond) {
; CHECK: [[CASE2]]:
; CHECK-NEXT: br label %[[SWITCH_BB]]
; CHECK: [[OUTER1]]:
+; CHECK-NEXT: call void @use(i32 [[DEF]])
; CHECK-NEXT: ret void
; CHECK: [[OUTER2]]:
+; CHECK-NEXT: call void @use(i32 [[DEF]])
; CHECK-NEXT: ret void
; CHECK: [[OUTER3]]:
+; CHECK-NEXT: call void @use(i32 [[DEF]])
; CHECK-NEXT: ret void
; CHECK: [[OUTER4]]:
+; CHECK-NEXT: call void @use(i32 [[DEF]])
; CHECK-NEXT: ret void
; CHECK: [[DEFAULT_DEST]]:
; CHECK-NEXT: ret void
@@ -39,17 +49,22 @@ entry:
br label %switch_bb
switch_bb:
- %phi = phi i32 [ 0, %entry ], [ %one, %case1_succ ], [ 2, %case2 ]
+ %phi = phi i32 [ 0, %entry ], [ %determine, %sub_switch_bb ], [ 2, %case2 ]
switch i32 %phi, label %default_dest [
i32 0, label %case1
i32 1, label %case2
+ i32 2, label %case3
]
case1:
- br label %case1_succ
+ br label %sub_switch_bb
+
+case3:
+ br label %sub_switch_bb
-case1_succ:
- %one = phi i32 [ 1, %case1 ]
+sub_switch_bb:
+ %determine = phi i32 [ 1, %case1 ], [ 3, %case3 ]
+ %def = load i32, ptr %p
switch i32 %cond, label %switch_bb [
i32 0, label %outer1
i32 1, label %outer2
@@ -61,56 +76,72 @@ case2:
br label %switch_bb
outer1:
+ call void @use(i32 %def)
ret void
outer2:
+ call void @use(i32 %def)
ret void
outer3:
+ call void @use(i32 %def)
ret void
outer4:
+ call void @use(i32 %def)
ret void
default_dest:
ret void
}
-define void @less_outer_uses_by_switch(i32 %cond, i1 %c1) {
+define void @less_outer_uses_by_switch(i32 %cond, ptr %p) {
; CHECK-LABEL: define void @less_outer_uses_by_switch(
-; CHECK-SAME: i32 [[COND:%.*]], i1 [[C1:%.*]]) {
+; CHECK-SAME: i32 [[COND:%.*]], ptr [[P:%.*]]) {
; CHECK-NEXT: [[ENTRY:.*]]:
; CHECK-NEXT: br label %[[SWITCH_BB:.*]]
; CHECK: [[SWITCH_BB]]:
-; CHECK-NEXT: [[PHI:%.*]] = phi i32 [ 0, %[[ENTRY]] ], [ poison, %[[CASE1_SUCC:.*]] ]
+; CHECK-NEXT: [[PHI:%.*]] = phi i32 [ 0, %[[ENTRY]] ], [ poison, %[[SUB_SWITCH_BB:.*]] ]
; CHECK-NEXT: switch i32 [[PHI]], label %[[DEFAULT_DEST:.*]] [
; CHECK-NEXT: i32 0, label %[[CASE1:.*]]
; CHECK-NEXT: i32 1, label %[[CASE2:.*]]
+; CHECK-NEXT: i32 2, label %[[CASE3:.*]]
; CHECK-NEXT: ]
; CHECK: [[SWITCH_BB_JT2:.*]]:
; CHECK-NEXT: [[PHI_JT2:%.*]] = phi i32 [ 2, %[[CASE2]] ]
+; CHECK-NEXT: br label %[[CASE3]]
+; CHECK: [[SWITCH_BB_JT3:.*]]:
+; CHECK-NEXT: [[PHI_JT3:%.*]] = phi i32 [ [[DETERMINE_JT3:%.*]], %[[SUB_SWITCH_BB_JT3:.*]] ]
; CHECK-NEXT: br label %[[DEFAULT_DEST]]
; CHECK: [[SWITCH_BB_JT1:.*]]:
-; CHECK-NEXT: [[PHI_JT1:%.*]] = phi i32 [ [[ONE_JT1:%.*]], %[[CASE1_SUCC_JT1:.*]] ]
+; CHECK-NEXT: [[PHI_JT1:%.*]] = phi i32 [ [[DETERMINE_JT1:%.*]], %[[SUB_SWITCH_BB_JT1:.*]] ]
; CHECK-NEXT: br label %[[CASE2]]
; CHECK: [[CASE1]]:
-; CHECK-NEXT: br label %[[CASE1_SUCC_JT1]]
-; CHECK: [[CASE1_SUCC]]:
+; CHECK-NEXT: br label %[[SUB_SWITCH_BB_JT1]]
+; CHECK: [[CASE3]]:
+; CHECK-NEXT: br label %[[SUB_SWITCH_BB_JT3]]
+; CHECK: [[SUB_SWITCH_BB]]:
+; CHECK-NEXT: [[DEF:%.*]] = load i32, ptr [[P]], align 4
; CHECK-NEXT: switch i32 [[COND]], label %[[SWITCH_BB]] [
; CHECK-NEXT: i32 0, label %[[OUTER1:.*]]
-; CHECK-NEXT: i32 1, label %[[OUTER2:.*]]
; CHECK-NEXT: ]
-; CHECK: [[CASE1_SUCC_JT1]]:
-; CHECK-NEXT: [[ONE_JT1]] = phi i32 [ 1, %[[CASE1]] ]
+; CHECK: [[SUB_SWITCH_BB_JT3]]:
+; CHECK-NEXT: [[DETERMINE_JT3]] = phi i32 [ 3, %[[CASE3]] ]
+; CHECK-NEXT: [[DEF_JT3:%.*]] = load i32, ptr [[P]], align 4
+; CHECK-NEXT: switch i32 [[COND]], label %[[SWITCH_BB_JT3]] [
+; CHECK-NEXT: i32 0, label %[[OUTER1]]
+; CHECK-NEXT: ]
+; CHECK: [[SUB_SWITCH_BB_JT1]]:
+; CHECK-NEXT: [[DETERMINE_JT1]] = phi i32 [ 1, %[[CASE1]] ]
+; CHECK-NEXT: [[DEF_JT1:%.*]] = load i32, ptr [[P]], align 4
; CHECK-NEXT: switch i32 [[COND]], label %[[SWITCH_BB_JT1]] [
; CHECK-NEXT: i32 0, label %[[OUTER1]]
-; CHECK-NEXT: i32 1, label %[[OUTER2]]
; CHECK-NEXT: ]
; CHECK: [[CASE2]]:
; CHECK-NEXT: br label %[[SWITCH_BB_JT2]]
; CHECK: [[OUTER1]]:
-; CHECK-NEXT: ret void
-; CHECK: [[OUTER2]]:
+; CHECK-NEXT: [[DEF1:%.*]] = phi i32 [ [[DEF_JT3]], %[[SUB_SWITCH_BB_JT3]] ], [ [[DEF_JT1]], %[[SUB_SWITCH_BB_JT1]] ], [ [[DEF]], %[[SUB_SWITCH_BB]] ]
+; CHECK-NEXT: call void @use(i32 [[DEF1]])
; CHECK-NEXT: ret void
; CHECK: [[DEFAULT_DEST]]:
; CHECK-NEXT: ret void
@@ -119,29 +150,31 @@ entry:
br label %switch_bb
switch_bb:
- %phi = phi i32 [ 0, %entry ], [ %one, %case1_succ ], [ 2, %case2 ]
+ %phi = phi i32 [ 0, %entry ], [ %determine, %sub_switch_bb ], [ 2, %case2 ]
switch i32 %phi, label %default_dest [
i32 0, label %case1
i32 1, label %case2
+ i32 2, label %case3
]
case1:
- br label %case1_succ
+ br label %sub_switch_bb
-case1_succ:
- %one = phi i32 [ 1, %case1 ]
+case3:
+ br label %sub_switch_bb
+
+sub_switch_bb:
+ %determine = phi i32 [ 1, %case1 ], [ 3, %case3 ]
+ %def = load i32, ptr %p
switch i32 %cond, label %switch_bb [
i32 0, label %outer1
- i32 1, label %outer2
]
case2:
br label %switch_bb
outer1:
- ret void
-
-outer2:
+ call void @use(i32 %def)
ret void
default_dest:
@@ -149,56 +182,82 @@ default_dest:
}
-define void @max_outer_uses_multi_preds(i32 %cond) {
+define void @max_outer_uses_multi_preds(i32 %cond, ptr %p) {
; CHECK-LABEL: define void @max_outer_uses_multi_preds(
-; CHECK-SAME: i32 [[COND:%.*]]) {
+; CHECK-SAME: i32 [[COND:%.*]], ptr [[P:%.*]]) {
; CHECK-NEXT: [[ENTRY:.*]]:
; CHECK-NEXT: br label %[[SWITCH_BB:.*]]
; CHECK: [[SWITCH_BB]]:
-; CHECK-NEXT: [[PHI:%.*]] = phi i32 [ 0, %[[ENTRY]] ], [ poison, %[[CASE1_SUCC:.*]] ]
+; CHECK-NEXT: [[PHI:%.*]] = phi i32 [ 0, %[[ENTRY]] ], [ poison, %[[SUB_SWITCH_BB:.*]] ]
; CHECK-NEXT: switch i32 [[PHI]], label %[[DEFAULT_DEST:.*]] [
; CHECK-NEXT: i32 0, label %[[CASE1:.*]]
; CHECK-NEXT: i32 1, label %[[CASE2:.*]]
; CHECK-NEXT: i32 2, label %[[CASE3:.*]]
+; CHECK-NEXT: i32 3, label %[[CASE4:.*]]
; CHECK-NEXT: ]
; CHECK: [[SWITCH_BB_JT2:.*]]:
; CHECK-NEXT: [[PHI_JT2:%.*]] = phi i32 [ 2, %[[CASE2]] ]
; CHECK-NEXT: br label %[[CASE3]]
+; CHECK: [[SWITCH_BB_JT3:.*]]:
+; CHECK-NEXT: [[PHI_JT3:%.*]] = phi i32 [ [[DETERMINE_JT3:%.*]], %[[SUB_SWITCH_BB_JT3:.*]] ]
+; CHECK-NEXT: br label %[[CASE4]]
; CHECK: [[SWITCH_BB_JT1:.*]]:
-; CHECK-NEXT: [[PHI_JT1:%.*]] = phi i32 [ [[ONE_JT1:%.*]], %[[CASE1_SUCC_JT1:.*]] ]
+; CHECK-NEXT: [[PHI_JT1:%.*]] = phi i32 [ [[DETERMINE_JT1:%.*]], %[[SUB_SWITCH_BB_JT1:.*]] ]
; CHECK-NEXT: br label %[[CASE2]]
; CHECK: [[CASE1]]:
-; CHECK-NEXT: br label %[[CASE1_SUCC_JT1]]
-; CHECK: [[CASE1_SUCC]]:
+; CHECK-NEXT: br label %[[SUB_SWITCH_BB_JT1]]
+; CHECK: [[CASE3]]:
+; CHECK-NEXT: br label %[[SUB_SWITCH_BB_JT3]]
+; CHECK: [[SUB_SWITCH_BB]]:
+; CHECK-NEXT: [[DEF:%.*]] = load i32, ptr [[P]], align 4
; CHECK-NEXT: switch i32 [[COND]], label %[[SWITCH_BB]] [
; CHECK-NEXT: i32 0, label %[[OUTER1:.*]]
; CHECK-NEXT: i32 1, label %[[OUTER2:.*]]
; CHECK-NEXT: i32 2, label %[[OUTER3:.*]]
; CHECK-NEXT: i32 3, label %[[OUTER4:.*]]
; CHECK-NEXT: ]
-; CHECK: [[CASE1_SUCC_JT1]]:
-; CHECK-NEXT: [[ONE_JT1]] = phi i32 [ 1, %[[CASE1]] ]
+; CHECK: [[SUB_SWITCH_BB_JT3]]:
+; CHECK-NEXT: [[DETERMINE_JT3]] = phi i32 [ 3, %[[CASE3]] ]
+; CHECK-NEXT: [[DEF_JT3:%.*]] = load i32, ptr [[P]], align 4
+; CHECK-NEXT: switch i32 [[COND]], label %[[SWITCH_BB_JT3]] [
+; CHECK-NEXT: i32 0, label %[[OUTER1]]
+; CHECK-NEXT: i32 1, label %[[OUTER2]]
+; CHECK-NEXT: i32 2, label %[[OUTER3]]
+; CHECK-NEXT: i32 3, label %[[OUTER4]]
+; CHECK-NEXT: ]
+; CHECK: [[SUB_SWITCH_BB_JT1]]:
+; CHECK-NEXT: [[DETERMINE_JT1]] = phi i32 [ 1, %[[CASE1]] ]
+; CHECK-NEXT: [[DEF_JT1:%.*]] = load i32, ptr [[P]], align 4
; CHECK-NEXT: switch i32 [[COND]], label %[[SWITCH_BB_JT1]] [
; CHECK-NEXT: i32 0, label %[[OUTER1]]
; CHECK-NEXT: i32 1, label %[[OUTER2]]
; CHECK-NEXT: i32 2, label %[[OUTER3]]
; CHECK-NEXT: i32 3, label %[[OUTER4]]
; CHECK-NEXT: ]
-; CHECK: [[CASE2]]:
-; CHECK-NEXT: br label %[[SWITCH_BB_JT2]]
-; CHECK: [[CASE3]]:
+; CHECK: [[CASE4]]:
+; CHECK-NEXT: [[DEF1:%.*]] = load i32, ptr [[P]], align 4
; CHECK-NEXT: switch i32 [[COND]], label %[[OUTER4]] [
; CHECK-NEXT: i32 0, label %[[OUTER1]]
; CHECK-NEXT: i32 1, label %[[OUTER2]]
; CHECK-NEXT: i32 2, label %[[OUTER3]]
; CHECK-NEXT: ]
+; CHECK: [[CASE2]]:
+; CHECK-NEXT: br label %[[SWITCH_BB_JT2]]
; CHECK: [[OUTER1]]:
+; CHECK-NEXT: [[PHI1:%.*]] = phi i32 [ [[DEF]], %[[SUB_SWITCH_BB]] ], [ [[DEF1]], %[[CASE4]] ], [ [[DEF_JT1]], %[[SUB_SWITCH_BB_JT1]] ], [ [[DEF_JT3]], %[[SUB_SWITCH_BB_JT3]] ]
+; CHECK-NEXT: call void @use(i32 [[PHI1]])
; CHECK-NEXT: ret void
; CHECK: [[OUTER2]]:
+; CHECK-NEXT: [[PHI2:%.*]] = phi i32 [ [[DEF]], %[[SUB_SWITCH_BB]] ], [ [[DEF1]], %[[CASE4]] ], [ [[DEF_JT1]], %[[SUB_SWITCH_BB_JT1]] ], [ [[DEF_JT3]], %[[SUB_SWITCH_BB_JT3]] ]
+; CHECK-NEXT: call void @use(i32 [[PHI2]])
; CHECK-NEXT: ret void
; CHECK: [[OUTER3]]:
+; CHECK-NEXT: [[PHI3:%.*]] = phi i32 [ [[DEF]], %[[SUB_SWITCH_BB]] ], [ [[DEF1]], %[[CASE4]] ], [ [[DEF_JT1]], %[[SUB_SWITCH_BB_JT1]] ], [ [[DEF_JT3]], %[[SUB_SWITCH_BB_JT3]] ]
+; CHECK-NEXT: call void @use(i32 [[PHI3]])
; CHECK-NEXT: ret void
; CHECK: [[OUTER4]]:
+; CHECK-NEXT: [[PHI4:%.*]] = phi i32 [ [[DEF]], %[[SUB_SWITCH_BB]] ], [ [[DEF1]], %[[CASE4]] ], [ [[DEF_JT1]], %[[SUB_SWITCH_BB_JT1]] ], [ [[DEF_JT3]], %[[SUB_SWITCH_BB_JT3]] ]
+; CHECK-NEXT: call void @use(i32 [[PHI4]])
; CHECK-NEXT: ret void
; CHECK: [[DEFAULT_DEST]]:
; CHECK-NEXT: ret void
@@ -207,18 +266,23 @@ entry:
br label %switch_bb
switch_bb:
- %phi = phi i32 [ 0, %entry ], [ %one, %case1_succ ], [ 2, %case2 ]
+ %phi = phi i32 [ 0, %entry ], [ %determine, %sub_switch_bb ], [ 2, %case2 ]
switch i32 %phi, label %default_dest [
i32 0, label %case1
i32 1, label %case2
i32 2, label %case3
+ i32 3, label %case4
]
case1:
- br label %case1_succ
+ br label %sub_switch_bb
+
+case3:
+ br label %sub_switch_bb
-case1_succ:
- %one = phi i32 [ 1, %case1 ]
+sub_switch_bb:
+ %determine = phi i32 [ 1, %case1 ], [ 3, %case3 ]
+ %def = load i32, ptr %p
switch i32 %cond, label %switch_bb [
i32 0, label %outer1
i32 1, label %outer2
@@ -226,26 +290,35 @@ case1_succ:
i32 3, label %outer4
]
-case2:
- br label %switch_bb
-
-case3:
+case4:
+ %def1 = load i32, ptr %p
switch i32 %cond, label %outer4 [
i32 0, label %outer1
i32 1, label %outer2
i32 2, label %outer3
]
+case2:
+ br label %switch_bb
+
outer1:
+ %phi1 = phi i32 [ %def, %sub_switch_bb ], [ %def1, %case4 ]
+ call void @use(i32 %phi1)
ret void
outer2:
+ %phi2 = phi i32 [ %def, %sub_switch_bb ], [ %def1, %case4 ]
+ call void @use(i32 %phi2)
ret void
outer3:
+ %phi3 = phi i32 [ %def, %sub_switch_bb ], [ %def1, %case4 ]
+ call void @use(i32 %phi3)
ret void
outer4:
+ %phi4 = phi i32 [ %def, %sub_switch_bb ], [ %def1, %case4 ]
+ call void @use(i32 %phi4)
ret void
default_dest:
More information about the llvm-commits
mailing list