diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
--- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -1355,6 +1355,25 @@
         Ops.push_back(Op->DoPHITranslation(PN->getParent(), InBB));
     }
 
+    // Check if incoming PHI value can be replaced with constant
+    // based on implied condition.
+    BranchInst *TerminatorBI = dyn_cast<BranchInst>(InBB->getTerminator());
+    const ICmpInst *ICmp = dyn_cast<ICmpInst>(&I);
+    if (TerminatorBI && TerminatorBI->isConditional() && ICmp) {
+      const Value *RHSOp0 = Ops[0];
+      const Value *RHSOp1 = Ops[1];
+      bool LHSIsTrue = TerminatorBI->getSuccessor(0) == PN->getParent();
+      std::optional<bool> ImpliedCond =
+          isImpliedCondition(TerminatorBI->getCondition(), ICmp->getPredicate(),
+                             RHSOp0, RHSOp1, DL, LHSIsTrue);
+      if (ImpliedCond) {
+        APInt Constant(I.getType()->getScalarSizeInBits(), ImpliedCond.value());
+        NewPhiValues.push_back(
+            ConstantVector::getIntegerValue(I.getType(), Constant));
+        continue;
+      }
+    }
+
     // Don't consider the simplification successful if we get back a constant
     // expression. That's just an instruction in hiding.
     // Also reject the case where we simplify back to the phi node. We wouldn't
diff --git a/llvm/test/Transforms/InstCombine/phi.ll b/llvm/test/Transforms/InstCombine/phi.ll
--- a/llvm/test/Transforms/InstCombine/phi.ll
+++ b/llvm/test/Transforms/InstCombine/phi.ll
@@ -1670,18 +1670,15 @@
 define i1 @cmp_eq_phi_node_can_fold_1(ptr %C) {
 ; CHECK-LABEL: @cmp_eq_phi_node_can_fold_1(
 ; CHECK-NEXT:    [[TMP1:%.*]] = load i8, ptr [[C:%.*]], align 1
-; CHECK-NEXT:    [[TMP2:%.*]] = zext i8 [[TMP1]] to i32
-; CHECK-NEXT:    [[TMP3:%.*]] = add nsw i32 [[TMP2]], -48
-; CHECK-NEXT:    [[TMP4:%.*]] = icmp eq i32 [[TMP3]], 0
-; CHECK-NEXT:    br i1 [[TMP4]], label [[SUB_IS_ZERO:%.*]], label [[JOIN:%.*]]
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp eq i8 [[TMP1]], 48
+; CHECK-NEXT:    br i1 [[TMP2]], label [[SUB_IS_ZERO:%.*]], label [[JOIN:%.*]]
 ; CHECK:       sub_is_zero:
-; CHECK-NEXT:    [[TMP5:%.*]] = getelementptr inbounds i8, ptr [[C]], i64 1
-; CHECK-NEXT:    [[TMP6:%.*]] = load i8, ptr [[TMP5]], align 1
-; CHECK-NEXT:    [[TMP7:%.*]] = zext i8 [[TMP6]] to i32
+; CHECK-NEXT:    [[TMP3:%.*]] = getelementptr inbounds i8, ptr [[C]], i64 1
+; CHECK-NEXT:    [[TMP4:%.*]] = load i8, ptr [[TMP3]], align 1
+; CHECK-NEXT:    [[TMP5:%.*]] = icmp eq i8 [[TMP4]], 0
 ; CHECK-NEXT:    br label [[JOIN]]
 ; CHECK:       join:
-; CHECK-NEXT:    [[TMP8:%.*]] = phi i32 [ [[TMP3]], [[TMP0:%.*]] ], [ [[TMP7]], [[SUB_IS_ZERO]] ]
-; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i32 [[TMP8]], 0
+; CHECK-NEXT:    [[CMP:%.*]] = phi i1 [ false, [[TMP0:%.*]] ], [ [[TMP5]], [[SUB_IS_ZERO]] ]
 ; CHECK-NEXT:    ret i1 [[CMP]]
 ;
   %1 = load i8, ptr %C, align 1
@@ -1705,25 +1702,20 @@
 define i1 @cmp_eq_phi_node_can_fold_2(ptr %C) {
 ; CHECK-LABEL: @cmp_eq_phi_node_can_fold_2(
 ; CHECK-NEXT:    [[TMP1:%.*]] = load i8, ptr [[C:%.*]], align 1
-; CHECK-NEXT:    [[TMP2:%.*]] = zext i8 [[TMP1]] to i32
-; CHECK-NEXT:    [[TMP3:%.*]] = add nsw i32 [[TMP2]], -48
-; CHECK-NEXT:    [[TMP4:%.*]] = icmp eq i32 [[TMP3]], 0
-; CHECK-NEXT:    br i1 [[TMP4]], label [[SUB_IS_ZERO:%.*]], label [[JOIN:%.*]]
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp eq i8 [[TMP1]], 48
+; CHECK-NEXT:    br i1 [[TMP2]], label [[SUB_IS_ZERO:%.*]], label [[JOIN:%.*]]
 ; CHECK:       sub_is_zero:
-; CHECK-NEXT:    [[TMP5:%.*]] = getelementptr inbounds i8, ptr [[C]], i64 1
-; CHECK-NEXT:    [[TMP6:%.*]] = load i8, ptr [[TMP5]], align 1
-; CHECK-NEXT:    [[TMP7:%.*]] = zext i8 [[TMP6]] to i32
-; CHECK-NEXT:    [[TMP8:%.*]] = add nsw i32 [[TMP7]], -49
-; CHECK-NEXT:    [[TMP9:%.*]] = icmp eq i32 [[TMP8]], 0
-; CHECK-NEXT:    br i1 [[TMP9]], label [[SUB_IS_ZERO1:%.*]], label [[JOIN]]
+; CHECK-NEXT:    [[TMP3:%.*]] = getelementptr inbounds i8, ptr [[C]], i64 1
+; CHECK-NEXT:    [[TMP4:%.*]] = load i8, ptr [[TMP3]], align 1
+; CHECK-NEXT:    [[TMP5:%.*]] = icmp eq i8 [[TMP4]], 49
+; CHECK-NEXT:    br i1 [[TMP5]], label [[SUB_IS_ZERO1:%.*]], label [[JOIN]]
 ; CHECK:       sub_is_zero1:
-; CHECK-NEXT:    [[TMP10:%.*]] = getelementptr inbounds i8, ptr [[C]], i64 2
-; CHECK-NEXT:    [[TMP11:%.*]] = load i8, ptr [[TMP10]], align 1
-; CHECK-NEXT:    [[TMP12:%.*]] = zext i8 [[TMP11]] to i32
+; CHECK-NEXT:    [[TMP6:%.*]] = getelementptr inbounds i8, ptr [[C]], i64 2
+; CHECK-NEXT:    [[TMP7:%.*]] = load i8, ptr [[TMP6]], align 1
+; CHECK-NEXT:    [[TMP8:%.*]] = icmp eq i8 [[TMP7]], 0
 ; CHECK-NEXT:    br label [[JOIN]]
 ; CHECK:       join:
-; CHECK-NEXT:    [[TMP13:%.*]] = phi i32 [ [[TMP3]], [[TMP0:%.*]] ], [ [[TMP8]], [[SUB_IS_ZERO]] ], [ [[TMP12]], [[SUB_IS_ZERO1]] ]
-; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i32 [[TMP13]], 0
+; CHECK-NEXT:    [[CMP:%.*]] = phi i1 [ false, [[TMP0:%.*]] ], [ false, [[SUB_IS_ZERO]] ], [ [[TMP8]], [[SUB_IS_ZERO1]] ]
 ; CHECK-NEXT:    ret i1 [[CMP]]
 ;
   %1 = load i8, ptr %C, align 1
@@ -1755,18 +1747,15 @@
 define i1 @cmp_ne_phi_node_can_fold_1(ptr %C) {
 ; CHECK-LABEL: @cmp_ne_phi_node_can_fold_1(
 ; CHECK-NEXT:    [[TMP1:%.*]] = load i8, ptr [[C:%.*]], align 1
-; CHECK-NEXT:    [[TMP2:%.*]] = zext i8 [[TMP1]] to i32
-; CHECK-NEXT:    [[TMP3:%.*]] = add nsw i32 [[TMP2]], -48
-; CHECK-NEXT:    [[TMP4:%.*]] = icmp eq i32 [[TMP3]], 0
-; CHECK-NEXT:    br i1 [[TMP4]], label [[SUB_IS_ZERO:%.*]], label [[JOIN:%.*]]
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp eq i8 [[TMP1]], 48
+; CHECK-NEXT:    br i1 [[TMP2]], label [[SUB_IS_ZERO:%.*]], label [[JOIN:%.*]]
 ; CHECK:       sub_is_zero:
-; CHECK-NEXT:    [[TMP5:%.*]] = getelementptr inbounds i8, ptr [[C]], i64 1
-; CHECK-NEXT:    [[TMP6:%.*]] = load i8, ptr [[TMP5]], align 1
-; CHECK-NEXT:    [[TMP7:%.*]] = zext i8 [[TMP6]] to i32
+; CHECK-NEXT:    [[TMP3:%.*]] = getelementptr inbounds i8, ptr [[C]], i64 1
+; CHECK-NEXT:    [[TMP4:%.*]] = load i8, ptr [[TMP3]], align 1
+; CHECK-NEXT:    [[TMP5:%.*]] = icmp ne i8 [[TMP4]], 0
 ; CHECK-NEXT:    br label [[JOIN]]
 ; CHECK:       join:
-; CHECK-NEXT:    [[TMP8:%.*]] = phi i32 [ [[TMP3]], [[TMP0:%.*]] ], [ [[TMP7]], [[SUB_IS_ZERO]] ]
-; CHECK-NEXT:    [[CMP:%.*]] = icmp ne i32 [[TMP8]], 0
+; CHECK-NEXT:    [[CMP:%.*]] = phi i1 [ true, [[TMP0:%.*]] ], [ [[TMP5]], [[SUB_IS_ZERO]] ]
 ; CHECK-NEXT:    ret i1 [[CMP]]
 ;
   %1 = load i8, ptr %C, align 1
@@ -1790,25 +1779,20 @@
 define i1 @cmp_ne_phi_node_can_fold_2(ptr %C) {
 ; CHECK-LABEL: @cmp_ne_phi_node_can_fold_2(
 ; CHECK-NEXT:    [[TMP1:%.*]] = load i8, ptr [[C:%.*]], align 1
-; CHECK-NEXT:    [[TMP2:%.*]] = zext i8 [[TMP1]] to i32
-; CHECK-NEXT:    [[TMP3:%.*]] = add nsw i32 [[TMP2]], -48
-; CHECK-NEXT:    [[TMP4:%.*]] = icmp eq i32 [[TMP3]], 0
-; CHECK-NEXT:    br i1 [[TMP4]], label [[SUB_IS_ZERO:%.*]], label [[JOIN:%.*]]
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp eq i8 [[TMP1]], 48
+; CHECK-NEXT:    br i1 [[TMP2]], label [[SUB_IS_ZERO:%.*]], label [[JOIN:%.*]]
 ; CHECK:       sub_is_zero:
-; CHECK-NEXT:    [[TMP5:%.*]] = getelementptr inbounds i8, ptr [[C]], i64 1
-; CHECK-NEXT:    [[TMP6:%.*]] = load i8, ptr [[TMP5]], align 1
-; CHECK-NEXT:    [[TMP7:%.*]] = zext i8 [[TMP6]] to i32
-; CHECK-NEXT:    [[TMP8:%.*]] = add nsw i32 [[TMP7]], -49
-; CHECK-NEXT:    [[TMP9:%.*]] = icmp eq i32 [[TMP8]], 0
-; CHECK-NEXT:    br i1 [[TMP9]], label [[SUB_IS_ZERO1:%.*]], label [[JOIN]]
+; CHECK-NEXT:    [[TMP3:%.*]] = getelementptr inbounds i8, ptr [[C]], i64 1
+; CHECK-NEXT:    [[TMP4:%.*]] = load i8, ptr [[TMP3]], align 1
+; CHECK-NEXT:    [[TMP5:%.*]] = icmp eq i8 [[TMP4]], 49
+; CHECK-NEXT:    br i1 [[TMP5]], label [[SUB_IS_ZERO1:%.*]], label [[JOIN]]
 ; CHECK:       sub_is_zero1:
-; CHECK-NEXT:    [[TMP10:%.*]] = getelementptr inbounds i8, ptr [[C]], i64 2
-; CHECK-NEXT:    [[TMP11:%.*]] = load i8, ptr [[TMP10]], align 1
-; CHECK-NEXT:    [[TMP12:%.*]] = zext i8 [[TMP11]] to i32
+; CHECK-NEXT:    [[TMP6:%.*]] = getelementptr inbounds i8, ptr [[C]], i64 2
+; CHECK-NEXT:    [[TMP7:%.*]] = load i8, ptr [[TMP6]], align 1
+; CHECK-NEXT:    [[TMP8:%.*]] = icmp ne i8 [[TMP7]], 0
 ; CHECK-NEXT:    br label [[JOIN]]
 ; CHECK:       join:
-; CHECK-NEXT:    [[TMP13:%.*]] = phi i32 [ [[TMP3]], [[TMP0:%.*]] ], [ [[TMP8]], [[SUB_IS_ZERO]] ], [ [[TMP12]], [[SUB_IS_ZERO1]] ]
-; CHECK-NEXT:    [[CMP:%.*]] = icmp ne i32 [[TMP13]], 0
+; CHECK-NEXT:    [[CMP:%.*]] = phi i1 [ true, [[TMP0:%.*]] ], [ true, [[SUB_IS_ZERO]] ], [ [[TMP8]], [[SUB_IS_ZERO1]] ]
 ; CHECK-NEXT:    ret i1 [[CMP]]
 ;
   %1 = load i8, ptr %C, align 1