[llvm] db3bbe0 - [Analysis] Unify most of the tracking between AssumptionCache and DomConditionCache
Noah Goldstein via llvm-commits
llvm-commits at lists.llvm.org
Mon Mar 4 14:53:48 PST 2024
Author: Noah Goldstein
Date: 2024-03-04T16:53:27-06:00
New Revision: db3bbe03f1c93100434a1394d293d13d4e5c1a2e
URL: https://github.com/llvm/llvm-project/commit/db3bbe03f1c93100434a1394d293d13d4e5c1a2e
DIFF: https://github.com/llvm/llvm-project/commit/db3bbe03f1c93100434a1394d293d13d4e5c1a2e.diff
LOG: [Analysis] Unify most of the tracking between AssumptionCache and DomConditionCache
This helps cover some missing cases in both and hopefully serves as
creating an easier framework for extending general condition based
analysis.
Closes #83161
Added:
Modified:
llvm/lib/Analysis/ValueTracking.cpp
llvm/test/Analysis/ValueTracking/numsignbits-from-assume.ll
llvm/test/Transforms/InstCombine/fpclass-from-dom-cond.ll
Removed:
################################################################################
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index dd78c165c4777f..69b2710420391d 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -9124,6 +9124,14 @@ void llvm::findValuesAffectedByCondition(
addValueAffectedByCondition(V, InsertAffected);
};
+ auto AddCmpOperands = [&AddAffected, IsAssume](Value *LHS, Value *RHS) {
+ if (IsAssume) {
+ AddAffected(LHS);
+ AddAffected(RHS);
+ } else if (match(RHS, m_Constant()))
+ AddAffected(LHS);
+ };
+
SmallVector<Value *, 8> Worklist;
SmallPtrSet<Value *, 8> Visited;
Worklist.push_back(Cond);
@@ -9135,65 +9143,62 @@ void llvm::findValuesAffectedByCondition(
CmpInst::Predicate Pred;
Value *A, *B, *X;
- if (IsAssume)
+ if (IsAssume) {
AddAffected(V);
+ if (match(V, m_Not(m_Value(X))))
+ AddAffected(X);
+ }
+
+ if (match(V, m_LogicalOp(m_Value(A), m_Value(B)))) {
+ // assume(A && B) is split to -> assume(A); assume(B);
+ // assume(!(A || B)) is split to -> assume(!A); assume(!B);
+ // Finally, assume(A || B) / assume(!(A && B)) generally don't provide
+ // enough information to be worth handling (intersection of information as
+ // opposed to union).
+ if (!IsAssume) {
+ Worklist.push_back(A);
+ Worklist.push_back(B);
+ }
+ } else if (match(V, m_ICmp(Pred, m_Value(A), m_Value(B)))) {
+ AddCmpOperands(A, B);
+
+ if (ICmpInst::isEquality(Pred)) {
+ if (match(B, m_ConstantInt())) {
+ // (X & C) or (X | C) or (X ^ C).
+ // (X << C) or (X >>_s C) or (X >>_u C).
+ if (match(A, m_BitwiseLogic(m_Value(X), m_ConstantInt())) ||
+ match(A, m_Shift(m_Value(X), m_ConstantInt())))
+ AddAffected(X);
+ }
+ } else {
+ // Handle (A + C1) u< C2, which is the canonical form of
+ // A > C3 && A < C4.
+ if (match(A, m_Add(m_Value(X), m_ConstantInt())) &&
+ match(B, m_ConstantInt()))
+ AddAffected(X);
+
+ // Handle icmp slt/sgt (bitcast X to int), 0/-1, which is supported
+ // by computeKnownFPClass().
+ if (match(A, m_ElementWiseBitCast(m_Value(X)))) {
+ if (Pred == ICmpInst::ICMP_SLT && match(B, m_Zero()))
+ InsertAffected(X);
+ else if (Pred == ICmpInst::ICMP_SGT && match(B, m_AllOnes()))
+ InsertAffected(X);
+ }
+ }
+ } else if (match(Cond, m_FCmp(Pred, m_Value(A), m_Value(B)))) {
+ AddCmpOperands(A, B);
- if (IsAssume && match(V, m_Not(m_Value(X))))
- AddAffected(X);
- if (!IsAssume && match(V, m_LogicalOp(m_Value(A), m_Value(B)))) {
- Worklist.push_back(A);
- Worklist.push_back(B);
- } else if (match(V, m_Cmp(Pred, m_Value(A), m_Value(B))) &&
- (IsAssume || isa<ICmpInst>(V))) {
- if (IsAssume || match(B, m_Constant())) {
+ // fcmp fneg(x), y
+ // fcmp fabs(x), y
+ // fcmp fneg(fabs(x)), y
+ if (match(A, m_FNeg(m_Value(A))))
+ AddAffected(A);
+ if (match(A, m_FAbs(m_Value(A))))
AddAffected(A);
- if (IsAssume)
- AddAffected(B);
-
- if (IsAssume ? (Pred == ICmpInst::ICMP_EQ)
- : ICmpInst::isEquality(Pred)) {
- if (match(B, m_ConstantInt())) {
- // (X & C) or (X | C) or (X ^ C).
- // (X << C) or (X >>_s C) or (X >>_u C).
- if (match(A, m_BitwiseLogic(m_Value(X), m_ConstantInt())) ||
- match(A, m_Shift(m_Value(X), m_ConstantInt())))
- AddAffected(X);
- }
- } else {
- if (Pred == ICmpInst::ICMP_NE)
- if (match(A, m_And(m_Value(X), m_Power2())) && match(B, m_Zero()))
- AddAffected(X);
-
- if (!IsAssume || Pred == ICmpInst::ICMP_ULT) {
- // Handle (A + C1) u< C2, which is the canonical form of
- // A > C3 && A < C4.
- if (match(A, m_Add(m_Value(X), m_ConstantInt())) &&
- match(B, m_ConstantInt()))
- AddAffected(X);
- }
- if (!IsAssume) {
- // Handle icmp slt/sgt (bitcast X to int), 0/-1, which is supported
- // by computeKnownFPClass().
- if ((Pred == ICmpInst::ICMP_SLT || Pred == ICmpInst::ICMP_SGT) &&
- match(A, m_ElementWiseBitCast(m_Value(X))))
- InsertAffected(X);
- }
- if (IsAssume && CmpInst::isFPPredicate(Pred)) {
- // fcmp fneg(x), y
- // fcmp fabs(x), y
- // fcmp fneg(fabs(x)), y
- if (match(A, m_FNeg(m_Value(A))))
- AddAffected(A);
- if (match(A, m_FAbs(m_Value(A))))
- AddAffected(A);
- }
- }
- }
- } else if ((!IsAssume &&
- match(Cond, m_FCmp(Pred, m_Value(A), m_Constant()))) ||
- match(Cond, m_Intrinsic<Intrinsic::is_fpclass>(m_Value(A),
- m_Value(B)))) {
+ } else if (match(V, m_Intrinsic<Intrinsic::is_fpclass>(m_Value(A),
+ m_Value()))) {
// Handle patterns that computeKnownFPClass() support.
AddAffected(A);
}
diff --git a/llvm/test/Analysis/ValueTracking/numsignbits-from-assume.ll b/llvm/test/Analysis/ValueTracking/numsignbits-from-assume.ll
index 00c66eeb599572..95ac98532da621 100644
--- a/llvm/test/Analysis/ValueTracking/numsignbits-from-assume.ll
+++ b/llvm/test/Analysis/ValueTracking/numsignbits-from-assume.ll
@@ -51,7 +51,7 @@ define i32 @computeNumSignBits_sub1(i32 %in) {
define i32 @computeNumSignBits_sub2(i32 %in) {
; CHECK-LABEL: @computeNumSignBits_sub2(
-; CHECK-NEXT: [[SUB:%.*]] = add i32 [[IN:%.*]], -1
+; CHECK-NEXT: [[SUB:%.*]] = add nsw i32 [[IN:%.*]], -1
; CHECK-NEXT: [[COND:%.*]] = icmp ult i32 [[SUB]], 43
; CHECK-NEXT: call void @llvm.assume(i1 [[COND]])
; CHECK-NEXT: [[SH:%.*]] = shl nuw nsw i32 [[SUB]], 3
diff --git a/llvm/test/Transforms/InstCombine/fpclass-from-dom-cond.ll b/llvm/test/Transforms/InstCombine/fpclass-from-dom-cond.ll
index d40cd7fd503ecc..d6706d76056eea 100644
--- a/llvm/test/Transforms/InstCombine/fpclass-from-dom-cond.ll
+++ b/llvm/test/Transforms/InstCombine/fpclass-from-dom-cond.ll
@@ -185,10 +185,9 @@ define i1 @test8(float %x) {
; CHECK-NEXT: [[COND:%.*]] = fcmp oeq float [[ABS]], 0x7FF0000000000000
; CHECK-NEXT: br i1 [[COND]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
; CHECK: if.then:
-; CHECK-NEXT: [[RET1:%.*]] = call i1 @llvm.is.fpclass.f32(float [[X]], i32 575)
-; CHECK-NEXT: ret i1 [[RET1]]
+; CHECK-NEXT: ret i1 true
; CHECK: if.else:
-; CHECK-NEXT: [[RET2:%.*]] = call i1 @llvm.is.fpclass.f32(float [[X]], i32 575)
+; CHECK-NEXT: [[RET2:%.*]] = call i1 @llvm.is.fpclass.f32(float [[X]], i32 59)
; CHECK-NEXT: ret i1 [[RET2]]
;
%abs = call float @llvm.fabs.f32(float %x)
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