[llvm] [LVI] Support no constant range of cast value in getEdgeValueLocal. (PR #157614)
Andreas Jonson via llvm-commits
llvm-commits at lists.llvm.org
Tue Sep 9 12:57:49 PDT 2025
https://github.com/andjo403 updated https://github.com/llvm/llvm-project/pull/157614
>From 3b6e08d0809f7c44068c95df12d550e481c96c3c Mon Sep 17 00:00:00 2001
From: Andreas Jonson <andjo403 at hotmail.com>
Date: Tue, 9 Sep 2025 07:05:00 +0200
Subject: [PATCH 1/4] [LVI] Add test of no constant range of cast and freeze
value in getEdgeValueLocal. (NFC)
---
.../CorrelatedValuePropagation/range.ll | 144 ++++++++++++++++++
1 file changed, 144 insertions(+)
diff --git a/llvm/test/Transforms/CorrelatedValuePropagation/range.ll b/llvm/test/Transforms/CorrelatedValuePropagation/range.ll
index 8d787fd5586ef..e2303e4a347c3 100644
--- a/llvm/test/Transforms/CorrelatedValuePropagation/range.ll
+++ b/llvm/test/Transforms/CorrelatedValuePropagation/range.ll
@@ -1235,6 +1235,150 @@ define i1 @neg_icmp_eq_range_call() {
ret i1 %cmp
}
+define i16 @return_range_for_edge_value_zext(i8 %a) {
+; CHECK-LABEL: define range(i16 0, 256) i16 @return_range_for_edge_value_zext(
+; CHECK-SAME: i8 [[A:%.*]]) {
+; CHECK-NEXT: [[ENTRY:.*:]]
+; CHECK-NEXT: [[B:%.*]] = zext i8 [[A]] to i16
+; CHECK-NEXT: br label %[[DISPATCH:.*]]
+; CHECK: [[DISPATCH]]:
+; CHECK-NEXT: [[CMP:%.*]] = icmp ult i8 [[A]], 98
+; CHECK-NEXT: br i1 [[CMP]], label %[[TARGET:.*]], label %[[DISPATCH]]
+; CHECK: [[TARGET]]:
+; CHECK-NEXT: ret i16 [[B]]
+;
+entry:
+ %b = zext i8 %a to i16
+ br label %dispatch
+
+dispatch:
+ %cmp = icmp ult i8 %a, 98
+ br i1 %cmp, label %target, label %dispatch
+
+target:
+ ret i16 %b
+}
+
+define i16 @return_range_for_edge_value_sext(i8 %a) {
+; CHECK-LABEL: define range(i16 -128, 128) i16 @return_range_for_edge_value_sext(
+; CHECK-SAME: i8 [[A:%.*]]) {
+; CHECK-NEXT: [[ENTRY:.*:]]
+; CHECK-NEXT: [[B:%.*]] = sext i8 [[A]] to i16
+; CHECK-NEXT: br label %[[DISPATCH:.*]]
+; CHECK: [[DISPATCH]]:
+; CHECK-NEXT: [[CMP:%.*]] = icmp ult i8 [[A]], 98
+; CHECK-NEXT: br i1 [[CMP]], label %[[TARGET:.*]], label %[[DISPATCH]]
+; CHECK: [[TARGET]]:
+; CHECK-NEXT: ret i16 [[B]]
+;
+entry:
+ %b = sext i8 %a to i16
+ br label %dispatch
+
+dispatch:
+ %cmp = icmp ult i8 %a, 98
+ br i1 %cmp, label %target, label %dispatch
+
+target:
+ ret i16 %b
+}
+
+define i8 @return_range_for_edge_value_trunc(i16 %a) {
+; CHECK-LABEL: define i8 @return_range_for_edge_value_trunc(
+; CHECK-SAME: i16 [[A:%.*]]) {
+; CHECK-NEXT: [[ENTRY:.*:]]
+; CHECK-NEXT: [[B:%.*]] = trunc i16 [[A]] to i8
+; CHECK-NEXT: br label %[[DISPATCH:.*]]
+; CHECK: [[DISPATCH]]:
+; CHECK-NEXT: [[CMP:%.*]] = icmp ult i16 [[A]], 98
+; CHECK-NEXT: br i1 [[CMP]], label %[[TARGET:.*]], label %[[DISPATCH]]
+; CHECK: [[TARGET]]:
+; CHECK-NEXT: ret i8 [[B]]
+;
+entry:
+ %b = trunc i16 %a to i8
+ br label %dispatch
+
+dispatch:
+ %cmp = icmp ult i16 %a, 98
+ br i1 %cmp, label %target, label %dispatch
+
+target:
+ ret i8 %b
+}
+
+define i8 @neg_return_range_for_edge_value_trunc(i16 %a) {
+; CHECK-LABEL: define i8 @neg_return_range_for_edge_value_trunc(
+; CHECK-SAME: i16 [[A:%.*]]) {
+; CHECK-NEXT: [[ENTRY:.*:]]
+; CHECK-NEXT: [[B:%.*]] = trunc i16 [[A]] to i8
+; CHECK-NEXT: br label %[[DISPATCH:.*]]
+; CHECK: [[DISPATCH]]:
+; CHECK-NEXT: [[CMP:%.*]] = icmp ugt i16 [[A]], 200
+; CHECK-NEXT: br i1 [[CMP]], label %[[TARGET:.*]], label %[[DISPATCH]]
+; CHECK: [[TARGET]]:
+; CHECK-NEXT: ret i8 [[B]]
+;
+entry:
+ %b = trunc i16 %a to i8
+ br label %dispatch
+
+dispatch:
+ %cmp = icmp ugt i16 %a, 200
+ br i1 %cmp, label %target, label %dispatch
+
+target:
+ ret i8 %b
+}
+
+define i8 @return_range_for_edge_value_trunc_nuw(i16 %a) {
+; CHECK-LABEL: define i8 @return_range_for_edge_value_trunc_nuw(
+; CHECK-SAME: i16 [[A:%.*]]) {
+; CHECK-NEXT: [[ENTRY:.*:]]
+; CHECK-NEXT: [[B:%.*]] = trunc nuw i16 [[A]] to i8
+; CHECK-NEXT: br label %[[DISPATCH:.*]]
+; CHECK: [[DISPATCH]]:
+; CHECK-NEXT: [[CMP:%.*]] = icmp ugt i16 [[A]], 200
+; CHECK-NEXT: br i1 [[CMP]], label %[[TARGET:.*]], label %[[DISPATCH]]
+; CHECK: [[TARGET]]:
+; CHECK-NEXT: ret i8 [[B]]
+;
+entry:
+ %b = trunc nuw i16 %a to i8
+ br label %dispatch
+
+dispatch:
+ %cmp = icmp ugt i16 %a, 200
+ br i1 %cmp, label %target, label %dispatch
+
+target:
+ ret i8 %b
+}
+
+define i8 @return_range_for_edge_value_freeze(i8 %a) {
+; CHECK-LABEL: define i8 @return_range_for_edge_value_freeze(
+; CHECK-SAME: i8 [[A:%.*]]) {
+; CHECK-NEXT: [[ENTRY:.*:]]
+; CHECK-NEXT: [[B:%.*]] = freeze i8 [[A]]
+; CHECK-NEXT: br label %[[DISPATCH:.*]]
+; CHECK: [[DISPATCH]]:
+; CHECK-NEXT: [[CMP:%.*]] = icmp ult i8 [[A]], 98
+; CHECK-NEXT: br i1 [[CMP]], label %[[TARGET:.*]], label %[[DISPATCH]]
+; CHECK: [[TARGET]]:
+; CHECK-NEXT: ret i8 [[B]]
+;
+entry:
+ %b = freeze i8 %a
+ br label %dispatch
+
+dispatch:
+ %cmp = icmp ult i8 %a, 98
+ br i1 %cmp, label %target, label %dispatch
+
+target:
+ ret i8 %b
+}
+
declare i16 @llvm.ctlz.i16(i16, i1)
declare i16 @llvm.cttz.i16(i16, i1)
declare i16 @llvm.ctpop.i16(i16)
>From 7cce3e7c1e2eca2892c54c5feb8298d6a9686e64 Mon Sep 17 00:00:00 2001
From: Andreas Jonson <andjo403 at hotmail.com>
Date: Tue, 9 Sep 2025 07:15:13 +0200
Subject: [PATCH 2/4] [LVI] Support no constant range of cast and freeze value
in getEdgeValueLocal.
---
llvm/lib/Analysis/LazyValueInfo.cpp | 18 ++++++++++++++++++
.../CorrelatedValuePropagation/range.ll | 10 +++++-----
.../JumpThreading/branch-debug-info2.ll | 2 +-
3 files changed, 24 insertions(+), 6 deletions(-)
diff --git a/llvm/lib/Analysis/LazyValueInfo.cpp b/llvm/lib/Analysis/LazyValueInfo.cpp
index c7b0ca97a8e43..84241be2c8816 100644
--- a/llvm/lib/Analysis/LazyValueInfo.cpp
+++ b/llvm/lib/Analysis/LazyValueInfo.cpp
@@ -1493,6 +1493,24 @@ LazyValueInfoImpl::getEdgeValueLocal(Value *Val, BasicBlock *BBFrom,
// br %Condition, label %then, label %else
APInt ConditionVal(1, isTrueDest ? 1 : 0);
Result = constantFoldUser(Usr, Condition, ConditionVal, DL);
+ } else if (isa<TruncInst, ZExtInst, SExtInst, FreezeInst>(Usr)) {
+ ValueLatticeElement OpLatticeVal =
+ *getValueFromCondition(Usr->getOperand(0), Condition,
+ isTrueDest, /*UseBlockValue*/ false);
+
+ if (isa<FreezeInst>(Usr) || !OpLatticeVal.isConstantRange())
+ return OpLatticeVal;
+
+ const unsigned ResultBitWidth =
+ Usr->getType()->getScalarSizeInBits();
+ if (auto *Trunc = dyn_cast<TruncInst>(Usr))
+ return ValueLatticeElement::getRange(
+ OpLatticeVal.getConstantRange().truncate(
+ ResultBitWidth, Trunc->getNoWrapKind()));
+
+ return ValueLatticeElement::getRange(
+ OpLatticeVal.getConstantRange().castOp(
+ cast<CastInst>(Usr)->getOpcode(), ResultBitWidth));
} else {
// If one of Val's operand has an inferred value, we may be able to
// infer the value of Val.
diff --git a/llvm/test/Transforms/CorrelatedValuePropagation/range.ll b/llvm/test/Transforms/CorrelatedValuePropagation/range.ll
index e2303e4a347c3..fd6722cfc1671 100644
--- a/llvm/test/Transforms/CorrelatedValuePropagation/range.ll
+++ b/llvm/test/Transforms/CorrelatedValuePropagation/range.ll
@@ -1236,7 +1236,7 @@ define i1 @neg_icmp_eq_range_call() {
}
define i16 @return_range_for_edge_value_zext(i8 %a) {
-; CHECK-LABEL: define range(i16 0, 256) i16 @return_range_for_edge_value_zext(
+; CHECK-LABEL: define range(i16 0, 98) i16 @return_range_for_edge_value_zext(
; CHECK-SAME: i8 [[A:%.*]]) {
; CHECK-NEXT: [[ENTRY:.*:]]
; CHECK-NEXT: [[B:%.*]] = zext i8 [[A]] to i16
@@ -1260,7 +1260,7 @@ target:
}
define i16 @return_range_for_edge_value_sext(i8 %a) {
-; CHECK-LABEL: define range(i16 -128, 128) i16 @return_range_for_edge_value_sext(
+; CHECK-LABEL: define range(i16 0, 98) i16 @return_range_for_edge_value_sext(
; CHECK-SAME: i8 [[A:%.*]]) {
; CHECK-NEXT: [[ENTRY:.*:]]
; CHECK-NEXT: [[B:%.*]] = sext i8 [[A]] to i16
@@ -1284,7 +1284,7 @@ target:
}
define i8 @return_range_for_edge_value_trunc(i16 %a) {
-; CHECK-LABEL: define i8 @return_range_for_edge_value_trunc(
+; CHECK-LABEL: define range(i8 0, 98) i8 @return_range_for_edge_value_trunc(
; CHECK-SAME: i16 [[A:%.*]]) {
; CHECK-NEXT: [[ENTRY:.*:]]
; CHECK-NEXT: [[B:%.*]] = trunc i16 [[A]] to i8
@@ -1332,7 +1332,7 @@ target:
}
define i8 @return_range_for_edge_value_trunc_nuw(i16 %a) {
-; CHECK-LABEL: define i8 @return_range_for_edge_value_trunc_nuw(
+; CHECK-LABEL: define range(i8 -55, 0) i8 @return_range_for_edge_value_trunc_nuw(
; CHECK-SAME: i16 [[A:%.*]]) {
; CHECK-NEXT: [[ENTRY:.*:]]
; CHECK-NEXT: [[B:%.*]] = trunc nuw i16 [[A]] to i8
@@ -1356,7 +1356,7 @@ target:
}
define i8 @return_range_for_edge_value_freeze(i8 %a) {
-; CHECK-LABEL: define i8 @return_range_for_edge_value_freeze(
+; CHECK-LABEL: define range(i8 0, 98) i8 @return_range_for_edge_value_freeze(
; CHECK-SAME: i8 [[A:%.*]]) {
; CHECK-NEXT: [[ENTRY:.*:]]
; CHECK-NEXT: [[B:%.*]] = freeze i8 [[A]]
diff --git a/llvm/test/Transforms/JumpThreading/branch-debug-info2.ll b/llvm/test/Transforms/JumpThreading/branch-debug-info2.ll
index 2bfa492832def..485b3bba06144 100644
--- a/llvm/test/Transforms/JumpThreading/branch-debug-info2.ll
+++ b/llvm/test/Transforms/JumpThreading/branch-debug-info2.ll
@@ -19,7 +19,7 @@ if.end.i60: ; preds = %shadow_to_ptr.exit
; Jump threading is going to fold the select in to the branch. Ensure debug
; info is not lost, and is merged from the select and the branch.
; CHECK-NOT: br i1 %cmp3.i, label %for.inc, label %ptr_to_shadow.exit
-; CHECK: br i1 %cmp3.i, label %for.inc, label %ptr_to_shadow.exit, !dbg [[DBG:![0-9]+]]
+; CHECK: br i1 %cmp3.i, label %for.inc, label %if.end22, !dbg [[DBG:![0-9]+]]
; CHECK: [[DBG]] = !DILocation(line: 9, column: 1, scope: !{{.*}})
br label %ptr_to_shadow.exit, !dbg !17
>From d75a408a7a9cdc524fecd8f62d7d3fe325201433 Mon Sep 17 00:00:00 2001
From: Andreas Jonson <andjo403 at hotmail.com>
Date: Tue, 9 Sep 2025 19:37:31 +0200
Subject: [PATCH 3/4] fixup! [LVI] Support no constant range of cast and
freeze value in getEdgeValueLocal.
---
llvm/lib/Analysis/LazyValueInfo.cpp | 4 ++--
.../CorrelatedValuePropagation/range.ll | 24 -------------------
2 files changed, 2 insertions(+), 26 deletions(-)
diff --git a/llvm/lib/Analysis/LazyValueInfo.cpp b/llvm/lib/Analysis/LazyValueInfo.cpp
index 84241be2c8816..90bae77bcf703 100644
--- a/llvm/lib/Analysis/LazyValueInfo.cpp
+++ b/llvm/lib/Analysis/LazyValueInfo.cpp
@@ -1493,12 +1493,12 @@ LazyValueInfoImpl::getEdgeValueLocal(Value *Val, BasicBlock *BBFrom,
// br %Condition, label %then, label %else
APInt ConditionVal(1, isTrueDest ? 1 : 0);
Result = constantFoldUser(Usr, Condition, ConditionVal, DL);
- } else if (isa<TruncInst, ZExtInst, SExtInst, FreezeInst>(Usr)) {
+ } else if (isa<TruncInst, ZExtInst, SExtInst>(Usr)) {
ValueLatticeElement OpLatticeVal =
*getValueFromCondition(Usr->getOperand(0), Condition,
isTrueDest, /*UseBlockValue*/ false);
- if (isa<FreezeInst>(Usr) || !OpLatticeVal.isConstantRange())
+ if (!OpLatticeVal.isConstantRange())
return OpLatticeVal;
const unsigned ResultBitWidth =
diff --git a/llvm/test/Transforms/CorrelatedValuePropagation/range.ll b/llvm/test/Transforms/CorrelatedValuePropagation/range.ll
index fd6722cfc1671..cb03161ac2797 100644
--- a/llvm/test/Transforms/CorrelatedValuePropagation/range.ll
+++ b/llvm/test/Transforms/CorrelatedValuePropagation/range.ll
@@ -1355,30 +1355,6 @@ target:
ret i8 %b
}
-define i8 @return_range_for_edge_value_freeze(i8 %a) {
-; CHECK-LABEL: define range(i8 0, 98) i8 @return_range_for_edge_value_freeze(
-; CHECK-SAME: i8 [[A:%.*]]) {
-; CHECK-NEXT: [[ENTRY:.*:]]
-; CHECK-NEXT: [[B:%.*]] = freeze i8 [[A]]
-; CHECK-NEXT: br label %[[DISPATCH:.*]]
-; CHECK: [[DISPATCH]]:
-; CHECK-NEXT: [[CMP:%.*]] = icmp ult i8 [[A]], 98
-; CHECK-NEXT: br i1 [[CMP]], label %[[TARGET:.*]], label %[[DISPATCH]]
-; CHECK: [[TARGET]]:
-; CHECK-NEXT: ret i8 [[B]]
-;
-entry:
- %b = freeze i8 %a
- br label %dispatch
-
-dispatch:
- %cmp = icmp ult i8 %a, 98
- br i1 %cmp, label %target, label %dispatch
-
-target:
- ret i8 %b
-}
-
declare i16 @llvm.ctlz.i16(i16, i1)
declare i16 @llvm.cttz.i16(i16, i1)
declare i16 @llvm.ctpop.i16(i16)
>From 46b35568aa2cf26708b6579418c601830e20ea41 Mon Sep 17 00:00:00 2001
From: Andreas Jonson <andjo403 at hotmail.com>
Date: Tue, 9 Sep 2025 21:57:34 +0200
Subject: [PATCH 4/4] fixup! fixup! [LVI] Support no constant range of cast
and freeze value in getEdgeValueLocal.
---
llvm/test/Transforms/CorrelatedValuePropagation/range.ll | 6 +++---
llvm/test/Transforms/JumpThreading/branch-debug-info2.ll | 2 +-
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/llvm/test/Transforms/CorrelatedValuePropagation/range.ll b/llvm/test/Transforms/CorrelatedValuePropagation/range.ll
index cb03161ac2797..860caf2624d42 100644
--- a/llvm/test/Transforms/CorrelatedValuePropagation/range.ll
+++ b/llvm/test/Transforms/CorrelatedValuePropagation/range.ll
@@ -1260,13 +1260,13 @@ target:
}
define i16 @return_range_for_edge_value_sext(i8 %a) {
-; CHECK-LABEL: define range(i16 0, 98) i16 @return_range_for_edge_value_sext(
+; CHECK-LABEL: define range(i16 -55, 0) i16 @return_range_for_edge_value_sext(
; CHECK-SAME: i8 [[A:%.*]]) {
; CHECK-NEXT: [[ENTRY:.*:]]
; CHECK-NEXT: [[B:%.*]] = sext i8 [[A]] to i16
; CHECK-NEXT: br label %[[DISPATCH:.*]]
; CHECK: [[DISPATCH]]:
-; CHECK-NEXT: [[CMP:%.*]] = icmp ult i8 [[A]], 98
+; CHECK-NEXT: [[CMP:%.*]] = icmp ugt i8 [[A]], -56
; CHECK-NEXT: br i1 [[CMP]], label %[[TARGET:.*]], label %[[DISPATCH]]
; CHECK: [[TARGET]]:
; CHECK-NEXT: ret i16 [[B]]
@@ -1276,7 +1276,7 @@ entry:
br label %dispatch
dispatch:
- %cmp = icmp ult i8 %a, 98
+ %cmp = icmp ugt i8 %a, -56
br i1 %cmp, label %target, label %dispatch
target:
diff --git a/llvm/test/Transforms/JumpThreading/branch-debug-info2.ll b/llvm/test/Transforms/JumpThreading/branch-debug-info2.ll
index 485b3bba06144..59b6ef51d670f 100644
--- a/llvm/test/Transforms/JumpThreading/branch-debug-info2.ll
+++ b/llvm/test/Transforms/JumpThreading/branch-debug-info2.ll
@@ -18,7 +18,7 @@ if.end.i60: ; preds = %shadow_to_ptr.exit
%spec.select.i = select i1 %cmp3.i, i32 -1, i32 %conv7.i, !dbg !17
; Jump threading is going to fold the select in to the branch. Ensure debug
; info is not lost, and is merged from the select and the branch.
-; CHECK-NOT: br i1 %cmp3.i, label %for.inc, label %ptr_to_shadow.exit
+; CHECK-NOT: br i1 %cmp3.i, label %for.inc, label %if.end22
; CHECK: br i1 %cmp3.i, label %for.inc, label %if.end22, !dbg [[DBG:![0-9]+]]
; CHECK: [[DBG]] = !DILocation(line: 9, column: 1, scope: !{{.*}})
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