[llvm] [InstCombine] fold `cond ? x : -x == 0` into `x == 0` (PR #85673)
via llvm-commits
llvm-commits at lists.llvm.org
Tue Mar 26 03:06:35 PDT 2024
https://github.com/SahilPatidar updated https://github.com/llvm/llvm-project/pull/85673
>From f23d911a0a89aacd012d8a2ca29db12dd206d6ac Mon Sep 17 00:00:00 2001
From: SahilPatidar <patidarsahil2001 at gmail.com>
Date: Mon, 18 Mar 2024 09:32:59 +0530
Subject: [PATCH 1/3] [InstCombine] FP fold, cond ? x : -x == 0 into x == 0
#85250
---
.../InstCombine/InstCombineCompares.cpp | 7 ++
llvm/test/Transforms/InstCombine/fcmp.ll | 107 ++++++++++++++++++
2 files changed, 114 insertions(+)
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
index 0dce0077bf1588..6d5ef3c6718554 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -7972,6 +7972,13 @@ Instruction *InstCombinerImpl::visitFCmpInst(FCmpInst &I) {
Constant *RHSC;
if (match(Op0, m_Instruction(LHSI)) && match(Op1, m_Constant(RHSC))) {
switch (LHSI->getOpcode()) {
+ case Instruction::Select:
+ if ((Pred == FCmpInst::FCMP_UEQ || Pred == FCmpInst::FCMP_OEQ ||
+ Pred == FCmpInst::FCMP_UNE || Pred == FCmpInst::FCMP_ONE) &&
+ match(LHSI, m_Select(m_Value(), m_Value(X), m_FNeg(m_Value(Y)))) &&
+ X == Y && match(RHSC, m_AnyZeroFP()))
+ return new FCmpInst(Pred, X, RHSC);
+ break;
case Instruction::PHI:
if (Instruction *NV = foldOpIntoPhi(I, cast<PHINode>(LHSI)))
return NV;
diff --git a/llvm/test/Transforms/InstCombine/fcmp.ll b/llvm/test/Transforms/InstCombine/fcmp.ll
index 159c84d0dd8aa9..ac5476159dd4ef 100644
--- a/llvm/test/Transforms/InstCombine/fcmp.ll
+++ b/llvm/test/Transforms/InstCombine/fcmp.ll
@@ -1284,3 +1284,110 @@ define <1 x i1> @bitcast_1vec_eq0(i32 %x) {
%cmp = fcmp oeq <1 x float> %f, zeroinitializer
ret <1 x i1> %cmp
}
+
+define i1 @fcmp_ueq_sel_x_negx(float %x) {
+; CHECK-LABEL: @fcmp_ueq_sel_x_negx(
+; CHECK-NEXT: [[RES:%.*]] = fcmp ueq float [[X:%.*]], 0.000000e+00
+; CHECK-NEXT: ret i1 [[RES]]
+;
+ %f = fcmp ueq float %x, 0.000000e+00
+ %neg = fneg fast float %x
+ %sel = select i1 %f, float %x, float %neg
+ %res = fcmp ueq float %sel, 0.000000e+00
+ ret i1 %res
+}
+
+define i1 @fcmp_une_sel_x_negx(float %x) {
+; CHECK-LABEL: @fcmp_une_sel_x_negx(
+; CHECK-NEXT: [[RES:%.*]] = fcmp une float [[X:%.*]], 0.000000e+00
+; CHECK-NEXT: ret i1 [[RES]]
+;
+ %f = fcmp une float %x, 0.000000e+00
+ %neg = fneg fast float %x
+ %sel = select i1 %f, float %x, float %neg
+ %res = fcmp une float %sel, 0.000000e+00
+ ret i1 %res
+}
+
+define i1 @fcmp_oeq_sel_x_negx(float %x) {
+; CHECK-LABEL: @fcmp_oeq_sel_x_negx(
+; CHECK-NEXT: [[RES:%.*]] = fcmp oeq float [[X:%.*]], 0.000000e+00
+; CHECK-NEXT: ret i1 [[RES]]
+;
+ %f = fcmp oeq float %x, 0.000000e+00
+ %neg = fneg fast float %x
+ %sel = select i1 %f, float %x, float %neg
+ %res = fcmp oeq float %sel, 0.000000e+00
+ ret i1 %res
+}
+
+define i1 @fcmp_one_sel_x_negx(float %x) {
+; CHECK-LABEL: @fcmp_one_sel_x_negx(
+; CHECK-NEXT: [[RES:%.*]] = fcmp one float [[X:%.*]], 0.000000e+00
+; CHECK-NEXT: ret i1 [[RES]]
+;
+ %f = fcmp one float %x, 0.000000e+00
+ %neg = fneg fast float %x
+ %sel = select i1 %f, float %x, float %neg
+ %res = fcmp one float %sel, 0.000000e+00
+ ret i1 %res
+}
+
+define <8 x i1> @fcmp_ueq_sel_x_negx_vec(<8 x float> %x) {
+; CHECK-LABEL: @fcmp_ueq_sel_x_negx_vec(
+; CHECK-NEXT: [[RES:%.*]] = fcmp ueq <8 x float> [[X:%.*]], zeroinitializer
+; CHECK-NEXT: ret <8 x i1> [[RES]]
+;
+ %f = fcmp ueq <8 x float> %x, zeroinitializer
+ %neg = fneg fast <8 x float> %x
+ %sel = select <8 x i1> %f, <8 x float> %x, <8 x float> %neg
+ %res = fcmp ueq <8 x float> %sel, zeroinitializer
+ ret <8 x i1> %res
+}
+
+define <8 x i1> @fcmp_une_sel_x_negx_vec(<8 x float> %x) {
+; CHECK-LABEL: @fcmp_une_sel_x_negx_vec(
+; CHECK-NEXT: [[RES:%.*]] = fcmp une <8 x float> [[X:%.*]], zeroinitializer
+; CHECK-NEXT: ret <8 x i1> [[RES]]
+;
+ %f = fcmp une <8 x float> %x, zeroinitializer
+ %neg = fneg fast <8 x float> %x
+ %sel = select <8 x i1> %f, <8 x float> %x, <8 x float> %neg
+ %res = fcmp une <8 x float> %sel, zeroinitializer
+ ret <8 x i1> %res
+}
+
+define <8 x i1> @fcmp_oeq_sel_x_negx_vec(<8 x float> %x) {
+; CHECK-LABEL: @fcmp_oeq_sel_x_negx_vec(
+; CHECK-NEXT: [[RES:%.*]] = fcmp oeq <8 x float> [[X:%.*]], zeroinitializer
+; CHECK-NEXT: ret <8 x i1> [[RES]]
+;
+ %f = fcmp oeq <8 x float> %x, zeroinitializer
+ %neg = fneg fast <8 x float> %x
+ %sel = select <8 x i1> %f, <8 x float> %x, <8 x float> %neg
+ %res = fcmp oeq <8 x float> %sel, zeroinitializer
+ ret <8 x i1> %res
+}
+
+define <8 x i1> @fcmp_one_sel_x_negx_vec(<8 x float> %x) {
+; CHECK-LABEL: @fcmp_one_sel_x_negx_vec(
+; CHECK-NEXT: [[RES:%.*]] = fcmp one <8 x float> [[X:%.*]], zeroinitializer
+; CHECK-NEXT: ret <8 x i1> [[RES]]
+;
+ %f = fcmp one <8 x float> %x, zeroinitializer
+ %neg = fneg fast <8 x float> %x
+ %sel = select <8 x i1> %f, <8 x float> %x, <8 x float> %neg
+ %res = fcmp one <8 x float> %sel, zeroinitializer
+ ret <8 x i1> %res
+}
+
+define i1 @fcmp_sel_x_negx_with_any_cond(float %x, i1 %c) {
+; CHECK-LABEL: @fcmp_sel_x_negx_with_any_cond(
+; CHECK-NEXT: [[RES:%.*]] = fcmp ueq float [[X:%.*]], 0.000000e+00
+; CHECK-NEXT: ret i1 [[RES]]
+;
+ %neg = fneg float %x
+ %sel = select i1 %c, float %x, float %neg
+ %res = fcmp ueq float %sel, 0.000000e+00
+ ret i1 %res
+}
>From 6aa1a1d65c9d5500ba6d4393a9af63f5a6d02b72 Mon Sep 17 00:00:00 2001
From: SahilPatidar <patidarsahil2001 at gmail.com>
Date: Sat, 23 Mar 2024 17:10:57 +0530
Subject: [PATCH 2/3] Fixes and updates tests
---
.../InstCombine/InstCombineCompares.cpp | 10 +--
llvm/test/Transforms/InstCombine/fcmp.ll | 64 ++++++++++++++++---
2 files changed, 61 insertions(+), 13 deletions(-)
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
index 6d5ef3c6718554..a821c1ece4b297 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -7973,11 +7973,11 @@ Instruction *InstCombinerImpl::visitFCmpInst(FCmpInst &I) {
if (match(Op0, m_Instruction(LHSI)) && match(Op1, m_Constant(RHSC))) {
switch (LHSI->getOpcode()) {
case Instruction::Select:
- if ((Pred == FCmpInst::FCMP_UEQ || Pred == FCmpInst::FCMP_OEQ ||
- Pred == FCmpInst::FCMP_UNE || Pred == FCmpInst::FCMP_ONE) &&
- match(LHSI, m_Select(m_Value(), m_Value(X), m_FNeg(m_Value(Y)))) &&
- X == Y && match(RHSC, m_AnyZeroFP()))
- return new FCmpInst(Pred, X, RHSC);
+ if (FCmpInst::isEquality(Pred) && match(RHSC, m_AnyZeroFP()) &&
+ (match(LHSI,
+ m_Select(m_Value(), m_Value(X), m_FNeg(m_Deferred(X)))) ||
+ match(LHSI, m_Select(m_Value(), m_FNeg(m_Value(X)), m_Deferred(X)))))
+ return new FCmpInst(Pred, X, RHSC, "", &I);
break;
case Instruction::PHI:
if (Instruction *NV = foldOpIntoPhi(I, cast<PHINode>(LHSI)))
diff --git a/llvm/test/Transforms/InstCombine/fcmp.ll b/llvm/test/Transforms/InstCombine/fcmp.ll
index ac5476159dd4ef..6d5af54f058e43 100644
--- a/llvm/test/Transforms/InstCombine/fcmp.ll
+++ b/llvm/test/Transforms/InstCombine/fcmp.ll
@@ -1291,7 +1291,7 @@ define i1 @fcmp_ueq_sel_x_negx(float %x) {
; CHECK-NEXT: ret i1 [[RES]]
;
%f = fcmp ueq float %x, 0.000000e+00
- %neg = fneg fast float %x
+ %neg = fneg float %x
%sel = select i1 %f, float %x, float %neg
%res = fcmp ueq float %sel, 0.000000e+00
ret i1 %res
@@ -1303,7 +1303,7 @@ define i1 @fcmp_une_sel_x_negx(float %x) {
; CHECK-NEXT: ret i1 [[RES]]
;
%f = fcmp une float %x, 0.000000e+00
- %neg = fneg fast float %x
+ %neg = fneg float %x
%sel = select i1 %f, float %x, float %neg
%res = fcmp une float %sel, 0.000000e+00
ret i1 %res
@@ -1315,7 +1315,7 @@ define i1 @fcmp_oeq_sel_x_negx(float %x) {
; CHECK-NEXT: ret i1 [[RES]]
;
%f = fcmp oeq float %x, 0.000000e+00
- %neg = fneg fast float %x
+ %neg = fneg float %x
%sel = select i1 %f, float %x, float %neg
%res = fcmp oeq float %sel, 0.000000e+00
ret i1 %res
@@ -1327,19 +1327,67 @@ define i1 @fcmp_one_sel_x_negx(float %x) {
; CHECK-NEXT: ret i1 [[RES]]
;
%f = fcmp one float %x, 0.000000e+00
- %neg = fneg fast float %x
+ %neg = fneg float %x
%sel = select i1 %f, float %x, float %neg
%res = fcmp one float %sel, 0.000000e+00
ret i1 %res
}
+define i1 @fcmp_ueq_sel_x_negx_nzero(float %x) {
+; CHECK-LABEL: @fcmp_ueq_sel_x_negx_nzero(
+; CHECK-NEXT: [[RES:%.*]] = fcmp ueq float [[X:%.*]], 0.000000e+00
+; CHECK-NEXT: ret i1 [[RES]]
+;
+ %f = fcmp ueq float %x, 0.000000e+00
+ %neg = fneg float %x
+ %sel = select i1 %f, float %x, float %neg
+ %res = fcmp ueq float %sel, -0.000000e+00
+ ret i1 %res
+}
+
+define i1 @fcmp_une_sel_x_negx_nzero(float %x) {
+; CHECK-LABEL: @fcmp_une_sel_x_negx_nzero(
+; CHECK-NEXT: [[RES:%.*]] = fcmp une float [[X:%.*]], 0.000000e+00
+; CHECK-NEXT: ret i1 [[RES]]
+;
+ %f = fcmp une float %x, 0.000000e+00
+ %neg = fneg float %x
+ %sel = select i1 %f, float %x, float %neg
+ %res = fcmp une float %sel, -0.000000e+00
+ ret i1 %res
+}
+
+define i1 @fcmp_oeq_sel_x_negx_nzero(float %x) {
+; CHECK-LABEL: @fcmp_oeq_sel_x_negx_nzero(
+; CHECK-NEXT: [[RES:%.*]] = fcmp oeq float [[X:%.*]], 0.000000e+00
+; CHECK-NEXT: ret i1 [[RES]]
+;
+ %f = fcmp oeq float %x, 0.000000e+00
+ %neg = fneg float %x
+ %sel = select i1 %f, float %x, float %neg
+ %res = fcmp oeq float %sel, -0.000000e+00
+ ret i1 %res
+}
+
+define i1 @fcmp_one_sel_x_negx_nzero(float %x) {
+; CHECK-LABEL: @fcmp_one_sel_x_negx_nzero(
+; CHECK-NEXT: [[RES:%.*]] = fcmp one float [[X:%.*]], 0.000000e+00
+; CHECK-NEXT: ret i1 [[RES]]
+;
+ %f = fcmp one float %x, 0.000000e+00
+ %neg = fneg float %x
+ %sel = select i1 %f, float %x, float %neg
+ %res = fcmp one float %sel, -0.000000e+00
+ ret i1 %res
+}
+
define <8 x i1> @fcmp_ueq_sel_x_negx_vec(<8 x float> %x) {
; CHECK-LABEL: @fcmp_ueq_sel_x_negx_vec(
; CHECK-NEXT: [[RES:%.*]] = fcmp ueq <8 x float> [[X:%.*]], zeroinitializer
; CHECK-NEXT: ret <8 x i1> [[RES]]
;
%f = fcmp ueq <8 x float> %x, zeroinitializer
- %neg = fneg fast <8 x float> %x
+ %neg = fneg <8 x float> %x
%sel = select <8 x i1> %f, <8 x float> %x, <8 x float> %neg
%res = fcmp ueq <8 x float> %sel, zeroinitializer
ret <8 x i1> %res
@@ -1351,7 +1399,7 @@ define <8 x i1> @fcmp_une_sel_x_negx_vec(<8 x float> %x) {
; CHECK-NEXT: ret <8 x i1> [[RES]]
;
%f = fcmp une <8 x float> %x, zeroinitializer
- %neg = fneg fast <8 x float> %x
+ %neg = fneg <8 x float> %x
%sel = select <8 x i1> %f, <8 x float> %x, <8 x float> %neg
%res = fcmp une <8 x float> %sel, zeroinitializer
ret <8 x i1> %res
@@ -1363,7 +1411,7 @@ define <8 x i1> @fcmp_oeq_sel_x_negx_vec(<8 x float> %x) {
; CHECK-NEXT: ret <8 x i1> [[RES]]
;
%f = fcmp oeq <8 x float> %x, zeroinitializer
- %neg = fneg fast <8 x float> %x
+ %neg = fneg <8 x float> %x
%sel = select <8 x i1> %f, <8 x float> %x, <8 x float> %neg
%res = fcmp oeq <8 x float> %sel, zeroinitializer
ret <8 x i1> %res
@@ -1375,7 +1423,7 @@ define <8 x i1> @fcmp_one_sel_x_negx_vec(<8 x float> %x) {
; CHECK-NEXT: ret <8 x i1> [[RES]]
;
%f = fcmp one <8 x float> %x, zeroinitializer
- %neg = fneg fast <8 x float> %x
+ %neg = fneg <8 x float> %x
%sel = select <8 x i1> %f, <8 x float> %x, <8 x float> %neg
%res = fcmp one <8 x float> %sel, zeroinitializer
ret <8 x i1> %res
>From 1acdfe49fb7545d9dec834f5de3e2a7f1e53c758 Mon Sep 17 00:00:00 2001
From: SahilPatidar <patidarsahil2001 at gmail.com>
Date: Tue, 26 Mar 2024 15:34:41 +0530
Subject: [PATCH 3/3] Add and update tests for any fp zero
---
.../InstCombine/InstCombineCompares.cpp | 1 +
llvm/test/Transforms/InstCombine/fcmp.ll | 85 ++++++++++++++++++-
2 files changed, 82 insertions(+), 4 deletions(-)
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
index a821c1ece4b297..2b9cd37a2630ec 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -7973,6 +7973,7 @@ Instruction *InstCombinerImpl::visitFCmpInst(FCmpInst &I) {
if (match(Op0, m_Instruction(LHSI)) && match(Op1, m_Constant(RHSC))) {
switch (LHSI->getOpcode()) {
case Instruction::Select:
+ // fcmp eq (cond ? x : -x), 0 --> fcmp eq x, 0
if (FCmpInst::isEquality(Pred) && match(RHSC, m_AnyZeroFP()) &&
(match(LHSI,
m_Select(m_Value(), m_Value(X), m_FNeg(m_Deferred(X)))) ||
diff --git a/llvm/test/Transforms/InstCombine/fcmp.ll b/llvm/test/Transforms/InstCombine/fcmp.ll
index 6d5af54f058e43..718ff8a4ed3af0 100644
--- a/llvm/test/Transforms/InstCombine/fcmp.ll
+++ b/llvm/test/Transforms/InstCombine/fcmp.ll
@@ -1429,13 +1429,90 @@ define <8 x i1> @fcmp_one_sel_x_negx_vec(<8 x float> %x) {
ret <8 x i1> %res
}
-define i1 @fcmp_sel_x_negx_with_any_cond(float %x, i1 %c) {
-; CHECK-LABEL: @fcmp_sel_x_negx_with_any_cond(
-; CHECK-NEXT: [[RES:%.*]] = fcmp ueq float [[X:%.*]], 0.000000e+00
+define <2 x i1> @fcmp_oeq_sel_x_negx_with_any_fpzero_vec(<2 x i1> %cond, <2 x float> %x) {
+; CHECK-LABEL: @fcmp_oeq_sel_x_negx_with_any_fpzero_vec(
+; CHECK-NEXT: [[ICMP:%.*]] = fcmp oeq <2 x float> [[X:%.*]], zeroinitializer
+; CHECK-NEXT: ret <2 x i1> [[ICMP]]
+;
+ %fneg = fneg <2 x float> %x
+ %sel = select <2 x i1> %cond, <2 x float> %x, <2 x float> %fneg
+ %icmp = fcmp oeq <2 x float> %sel, <float 0.0, float -0.0>
+ ret <2 x i1> %icmp
+}
+
+define <2 x i1> @fcmp_one_sel_x_negx_with_any_fpzero_vec(<2 x i1> %cond, <2 x float> %x) {
+; CHECK-LABEL: @fcmp_one_sel_x_negx_with_any_fpzero_vec(
+; CHECK-NEXT: [[ICMP:%.*]] = fcmp one <2 x float> [[X:%.*]], zeroinitializer
+; CHECK-NEXT: ret <2 x i1> [[ICMP]]
+;
+ %fneg = fneg <2 x float> %x
+ %sel = select <2 x i1> %cond, <2 x float> %x, <2 x float> %fneg
+ %icmp = fcmp one <2 x float> %sel, <float 0.0, float -0.0>
+ ret <2 x i1> %icmp
+}
+
+define <2 x i1> @fcmp_ueq_sel_x_negx_with_any_fpzero_vec(<2 x i1> %cond, <2 x float> %x) {
+; CHECK-LABEL: @fcmp_ueq_sel_x_negx_with_any_fpzero_vec(
+; CHECK-NEXT: [[ICMP:%.*]] = fcmp ueq <2 x float> [[X:%.*]], zeroinitializer
+; CHECK-NEXT: ret <2 x i1> [[ICMP]]
+;
+ %fneg = fneg <2 x float> %x
+ %sel = select <2 x i1> %cond, <2 x float> %x, <2 x float> %fneg
+ %icmp = fcmp ueq <2 x float> %sel, <float 0.0, float -0.0>
+ ret <2 x i1> %icmp
+}
+
+define <2 x i1> @fcmp_une_sel_x_negx_with_any_fpzero_vec(<2 x i1> %cond, <2 x float> %x) {
+; CHECK-LABEL: @fcmp_une_sel_x_negx_with_any_fpzero_vec(
+; CHECK-NEXT: [[ICMP:%.*]] = fcmp une <2 x float> [[X:%.*]], zeroinitializer
+; CHECK-NEXT: ret <2 x i1> [[ICMP]]
+;
+ %fneg = fneg <2 x float> %x
+ %sel = select <2 x i1> %cond, <2 x float> %x, <2 x float> %fneg
+ %icmp = fcmp une <2 x float> %sel, <float 0.0, float -0.0>
+ ret <2 x i1> %icmp
+}
+
+define i1 @fcmp_ueq_sel_x_negx_with_fmf(float %x, i1 %c) {
+; CHECK-LABEL: @fcmp_ueq_sel_x_negx_with_fmf(
+; CHECK-NEXT: [[RES:%.*]] = fcmp fast ueq float [[X:%.*]], 0.000000e+00
; CHECK-NEXT: ret i1 [[RES]]
;
%neg = fneg float %x
%sel = select i1 %c, float %x, float %neg
- %res = fcmp ueq float %sel, 0.000000e+00
+ %res = fcmp fast ueq float %sel, 0.000000e+00
+ ret i1 %res
+}
+
+define i1 @fcmp_une_sel_x_negx_with_fmf(float %x, i1 %c) {
+; CHECK-LABEL: @fcmp_une_sel_x_negx_with_fmf(
+; CHECK-NEXT: [[RES:%.*]] = fcmp fast une float [[X:%.*]], 0.000000e+00
+; CHECK-NEXT: ret i1 [[RES]]
+;
+ %neg = fneg float %x
+ %sel = select i1 %c, float %x, float %neg
+ %res = fcmp fast une float %sel, 0.000000e+00
+ ret i1 %res
+}
+
+define i1 @fcmp_oeq_sel_x_negx_with_fmf(float %x, i1 %c) {
+; CHECK-LABEL: @fcmp_oeq_sel_x_negx_with_fmf(
+; CHECK-NEXT: [[RES:%.*]] = fcmp fast oeq float [[X:%.*]], 0.000000e+00
+; CHECK-NEXT: ret i1 [[RES]]
+;
+ %neg = fneg float %x
+ %sel = select i1 %c, float %x, float %neg
+ %res = fcmp fast oeq float %sel, 0.000000e+00
+ ret i1 %res
+}
+
+define i1 @fcmp_one_sel_x_negx_with_fmf(float %x, i1 %c) {
+; CHECK-LABEL: @fcmp_one_sel_x_negx_with_fmf(
+; CHECK-NEXT: [[RES:%.*]] = fcmp fast one float [[X:%.*]], 0.000000e+00
+; CHECK-NEXT: ret i1 [[RES]]
+;
+ %neg = fneg float %x
+ %sel = select i1 %c, float %x, float %neg
+ %res = fcmp fast one float %sel, 0.000000e+00
ret i1 %res
}
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