[lldb] [clang] [libc] [libcxxabi] [libunwind] [llvm] [flang] [libcxx] [lld] [clang-tools-extra] [compiler-rt] [PowerPC] Combine sub within setcc back to sext (PR #66978)
Qiu Chaofan via cfe-commits
cfe-commits at lists.llvm.org
Wed Nov 29 18:12:47 PST 2023
https://github.com/ecnelises updated https://github.com/llvm/llvm-project/pull/66978
>From 2a7b9be6cd0705590c85c51b35ea99fe053aaf47 Mon Sep 17 00:00:00 2001
From: Qiu Chaofan <qiucofan at cn.ibm.com>
Date: Wed, 6 Sep 2023 16:16:34 +0800
Subject: [PATCH 1/4] [PowerPC] Combine sub within setcc back to sext
---
llvm/lib/Target/PowerPC/PPCISelLowering.cpp | 37 +++++++++++++-----
llvm/test/CodeGen/PowerPC/setcc-to-sub.ll | 42 +++++++++++++++++++++
2 files changed, 69 insertions(+), 10 deletions(-)
diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
index f4e3531980d165f..4659ebef35ecf62 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -14407,15 +14407,18 @@ SDValue PPCTargetLowering::DAGCombineExtBoolTrunc(SDNode *N,
ShiftCst);
}
-SDValue PPCTargetLowering::combineSetCC(SDNode *N,
- DAGCombinerInfo &DCI) const {
- assert(N->getOpcode() == ISD::SETCC &&
- "Should be called with a SETCC node");
+SDValue PPCTargetLowering::combineSetCC(SDNode *N, DAGCombinerInfo &DCI) const {
+ assert(N->getOpcode() == ISD::SETCC && "Should be called with a SETCC node");
ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(2))->get();
+ SDValue LHS = N->getOperand(0);
+ SDValue RHS = N->getOperand(1);
+ SDLoc DL(N);
+ SelectionDAG &DAG = DCI.DAG;
+ EVT VT = N->getValueType(0);
+ EVT OpVT = LHS.getValueType();
+
if (CC == ISD::SETNE || CC == ISD::SETEQ) {
- SDValue LHS = N->getOperand(0);
- SDValue RHS = N->getOperand(1);
// If there is a '0 - y' pattern, canonicalize the pattern to the RHS.
if (LHS.getOpcode() == ISD::SUB && isNullConstant(LHS.getOperand(0)) &&
@@ -14426,15 +14429,29 @@ SDValue PPCTargetLowering::combineSetCC(SDNode *N,
// x != 0-y --> x+y != 0
if (RHS.getOpcode() == ISD::SUB && isNullConstant(RHS.getOperand(0)) &&
RHS.hasOneUse()) {
- SDLoc DL(N);
- SelectionDAG &DAG = DCI.DAG;
- EVT VT = N->getValueType(0);
- EVT OpVT = LHS.getValueType();
SDValue Add = DAG.getNode(ISD::ADD, DL, OpVT, LHS, RHS.getOperand(1));
return DAG.getSetCC(DL, VT, Add, DAG.getConstant(0, DL, OpVT), CC);
}
}
+ // Combine (a-2^(M-1)) => sext(trunc(a, M), 64)
+ if (CC == ISD::SETULT && LHS.getOpcode() == ISD::ADD && OpVT == MVT::i64 &&
+ isa<ConstantSDNode>(RHS) && isa<ConstantSDNode>(LHS.getOperand(1))) {
+ uint64_t ShiftVal =
+ ~(cast<ConstantSDNode>(LHS.getOperand(1))->getZExtValue()) + 1;
+ uint64_t CmpVal = ~(cast<ConstantSDNode>(RHS)->getZExtValue()) + 1;
+ if (isPowerOf2_64(ShiftVal) && ShiftVal << 1 == CmpVal) {
+ unsigned DestBits = Log2_64(CmpVal);
+ if (DestBits == 8 || DestBits == 16 || DestBits == 32) {
+ SDValue Conv =
+ DAG.getSExtOrTrunc(DAG.getSExtOrTrunc(LHS.getOperand(0), DL,
+ MVT::getIntegerVT(DestBits)),
+ DL, OpVT);
+ return DAG.getSetCC(DL, VT, LHS.getOperand(0), Conv, ISD::SETNE);
+ }
+ }
+ }
+
return DAGCombineTruncBoolExt(N, DCI);
}
diff --git a/llvm/test/CodeGen/PowerPC/setcc-to-sub.ll b/llvm/test/CodeGen/PowerPC/setcc-to-sub.ll
index 13c629b6349450c..ce75b77eed29666 100644
--- a/llvm/test/CodeGen/PowerPC/setcc-to-sub.ll
+++ b/llvm/test/CodeGen/PowerPC/setcc-to-sub.ll
@@ -89,6 +89,48 @@ entry:
ret i1 %cmp.i5
}
+define zeroext i1 @test5(i64 %a) {
+; CHECK-LABEL: test5:
+; CHECK: # %bb.0: # %entry
+; CHECK-NEXT: extsw 4, 3
+; CHECK-NEXT: xor 3, 3, 4
+; CHECK-NEXT: addic 4, 3, -1
+; CHECK-NEXT: subfe 3, 4, 3
+; CHECK-NEXT: blr
+entry:
+ %0 = add i64 %a, -2147483648
+ %cmp = icmp ult i64 %0, -4294967296
+ ret i1 %cmp
+}
+
+define zeroext i1 @test6(i64 %a) {
+; CHECK-LABEL: test6:
+; CHECK: # %bb.0: # %entry
+; CHECK-NEXT: extsh 4, 3
+; CHECK-NEXT: xor 3, 3, 4
+; CHECK-NEXT: addic 4, 3, -1
+; CHECK-NEXT: subfe 3, 4, 3
+; CHECK-NEXT: blr
+entry:
+ %0 = add i64 %a, -32768
+ %cmp = icmp ult i64 %0, -65536
+ ret i1 %cmp
+}
+
+define zeroext i1 @test7(i64 %a) {
+; CHECK-LABEL: test7:
+; CHECK: # %bb.0: # %entry
+; CHECK-NEXT: extsb 4, 3
+; CHECK-NEXT: xor 3, 3, 4
+; CHECK-NEXT: addic 4, 3, -1
+; CHECK-NEXT: subfe 3, 4, 3
+; CHECK-NEXT: blr
+entry:
+ %0 = add i64 %a, -128
+ %cmp = icmp ult i64 %0, -256
+ ret i1 %cmp
+}
+
!1 = !{!2, !2, i64 0}
!2 = !{!"int", !3, i64 0}
!3 = !{!"omnipotent char", !4, i64 0}
>From fbb7e6362d6223f8e0ee6014e000c1cc5ae6e777 Mon Sep 17 00:00:00 2001
From: Qiu Chaofan <qiucofan at cn.ibm.com>
Date: Wed, 6 Sep 2023 16:16:34 +0800
Subject: [PATCH 2/4] [PowerPC] Combine sub within setcc back to sext
---
llvm/lib/Target/PowerPC/PPCISelLowering.cpp | 37 +++++++++++++-----
llvm/test/CodeGen/PowerPC/setcc-to-sub.ll | 42 +++++++++++++++++++++
2 files changed, 69 insertions(+), 10 deletions(-)
diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
index f4e3531980d165f..4659ebef35ecf62 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -14407,15 +14407,18 @@ SDValue PPCTargetLowering::DAGCombineExtBoolTrunc(SDNode *N,
ShiftCst);
}
-SDValue PPCTargetLowering::combineSetCC(SDNode *N,
- DAGCombinerInfo &DCI) const {
- assert(N->getOpcode() == ISD::SETCC &&
- "Should be called with a SETCC node");
+SDValue PPCTargetLowering::combineSetCC(SDNode *N, DAGCombinerInfo &DCI) const {
+ assert(N->getOpcode() == ISD::SETCC && "Should be called with a SETCC node");
ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(2))->get();
+ SDValue LHS = N->getOperand(0);
+ SDValue RHS = N->getOperand(1);
+ SDLoc DL(N);
+ SelectionDAG &DAG = DCI.DAG;
+ EVT VT = N->getValueType(0);
+ EVT OpVT = LHS.getValueType();
+
if (CC == ISD::SETNE || CC == ISD::SETEQ) {
- SDValue LHS = N->getOperand(0);
- SDValue RHS = N->getOperand(1);
// If there is a '0 - y' pattern, canonicalize the pattern to the RHS.
if (LHS.getOpcode() == ISD::SUB && isNullConstant(LHS.getOperand(0)) &&
@@ -14426,15 +14429,29 @@ SDValue PPCTargetLowering::combineSetCC(SDNode *N,
// x != 0-y --> x+y != 0
if (RHS.getOpcode() == ISD::SUB && isNullConstant(RHS.getOperand(0)) &&
RHS.hasOneUse()) {
- SDLoc DL(N);
- SelectionDAG &DAG = DCI.DAG;
- EVT VT = N->getValueType(0);
- EVT OpVT = LHS.getValueType();
SDValue Add = DAG.getNode(ISD::ADD, DL, OpVT, LHS, RHS.getOperand(1));
return DAG.getSetCC(DL, VT, Add, DAG.getConstant(0, DL, OpVT), CC);
}
}
+ // Combine (a-2^(M-1)) => sext(trunc(a, M), 64)
+ if (CC == ISD::SETULT && LHS.getOpcode() == ISD::ADD && OpVT == MVT::i64 &&
+ isa<ConstantSDNode>(RHS) && isa<ConstantSDNode>(LHS.getOperand(1))) {
+ uint64_t ShiftVal =
+ ~(cast<ConstantSDNode>(LHS.getOperand(1))->getZExtValue()) + 1;
+ uint64_t CmpVal = ~(cast<ConstantSDNode>(RHS)->getZExtValue()) + 1;
+ if (isPowerOf2_64(ShiftVal) && ShiftVal << 1 == CmpVal) {
+ unsigned DestBits = Log2_64(CmpVal);
+ if (DestBits == 8 || DestBits == 16 || DestBits == 32) {
+ SDValue Conv =
+ DAG.getSExtOrTrunc(DAG.getSExtOrTrunc(LHS.getOperand(0), DL,
+ MVT::getIntegerVT(DestBits)),
+ DL, OpVT);
+ return DAG.getSetCC(DL, VT, LHS.getOperand(0), Conv, ISD::SETNE);
+ }
+ }
+ }
+
return DAGCombineTruncBoolExt(N, DCI);
}
diff --git a/llvm/test/CodeGen/PowerPC/setcc-to-sub.ll b/llvm/test/CodeGen/PowerPC/setcc-to-sub.ll
index 13c629b6349450c..ce75b77eed29666 100644
--- a/llvm/test/CodeGen/PowerPC/setcc-to-sub.ll
+++ b/llvm/test/CodeGen/PowerPC/setcc-to-sub.ll
@@ -89,6 +89,48 @@ entry:
ret i1 %cmp.i5
}
+define zeroext i1 @test5(i64 %a) {
+; CHECK-LABEL: test5:
+; CHECK: # %bb.0: # %entry
+; CHECK-NEXT: extsw 4, 3
+; CHECK-NEXT: xor 3, 3, 4
+; CHECK-NEXT: addic 4, 3, -1
+; CHECK-NEXT: subfe 3, 4, 3
+; CHECK-NEXT: blr
+entry:
+ %0 = add i64 %a, -2147483648
+ %cmp = icmp ult i64 %0, -4294967296
+ ret i1 %cmp
+}
+
+define zeroext i1 @test6(i64 %a) {
+; CHECK-LABEL: test6:
+; CHECK: # %bb.0: # %entry
+; CHECK-NEXT: extsh 4, 3
+; CHECK-NEXT: xor 3, 3, 4
+; CHECK-NEXT: addic 4, 3, -1
+; CHECK-NEXT: subfe 3, 4, 3
+; CHECK-NEXT: blr
+entry:
+ %0 = add i64 %a, -32768
+ %cmp = icmp ult i64 %0, -65536
+ ret i1 %cmp
+}
+
+define zeroext i1 @test7(i64 %a) {
+; CHECK-LABEL: test7:
+; CHECK: # %bb.0: # %entry
+; CHECK-NEXT: extsb 4, 3
+; CHECK-NEXT: xor 3, 3, 4
+; CHECK-NEXT: addic 4, 3, -1
+; CHECK-NEXT: subfe 3, 4, 3
+; CHECK-NEXT: blr
+entry:
+ %0 = add i64 %a, -128
+ %cmp = icmp ult i64 %0, -256
+ ret i1 %cmp
+}
+
!1 = !{!2, !2, i64 0}
!2 = !{!"int", !3, i64 0}
!3 = !{!"omnipotent char", !4, i64 0}
>From 7483e99e84cad30105f294caf8e7d556b89d3ac9 Mon Sep 17 00:00:00 2001
From: Qiu Chaofan <qiucofan at cn.ibm.com>
Date: Tue, 21 Nov 2023 13:57:39 +0800
Subject: [PATCH 3/4] Support i16 to i32 case
---
llvm/lib/Target/PowerPC/PPCISelLowering.cpp | 52 +++++++++++++++------
llvm/test/CodeGen/PowerPC/setcc-to-sub.ll | 23 ++++-----
2 files changed, 48 insertions(+), 27 deletions(-)
diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
index 6cac37d5b940039..d46396ae6b25dc5 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -14436,20 +14436,44 @@ SDValue PPCTargetLowering::combineSetCC(SDNode *N, DAGCombinerInfo &DCI) const {
}
}
- // Combine (a-2^(M-1)) => sext(trunc(a, M), 64)
- if (CC == ISD::SETULT && LHS.getOpcode() == ISD::ADD && OpVT == MVT::i64 &&
- isa<ConstantSDNode>(RHS) && isa<ConstantSDNode>(LHS.getOperand(1))) {
- uint64_t ShiftVal =
- ~(cast<ConstantSDNode>(LHS.getOperand(1))->getZExtValue()) + 1;
- uint64_t CmpVal = ~(cast<ConstantSDNode>(RHS)->getZExtValue()) + 1;
- if (isPowerOf2_64(ShiftVal) && ShiftVal << 1 == CmpVal) {
- unsigned DestBits = Log2_64(CmpVal);
- if (DestBits == 8 || DestBits == 16 || DestBits == 32) {
- SDValue Conv =
- DAG.getSExtOrTrunc(DAG.getSExtOrTrunc(LHS.getOperand(0), DL,
- MVT::getIntegerVT(DestBits)),
- DL, OpVT);
- return DAG.getSetCC(DL, VT, LHS.getOperand(0), Conv, ISD::SETNE);
+ if (CC == ISD::SETULT && isa<ConstantSDNode>(RHS)) {
+ uint64_t RHSVal = cast<ConstantSDNode>(RHS)->getZExtValue();
+ if (LHS.getOpcode() == ISD::ADD && isa<ConstantSDNode>(LHS.getOperand(1))) {
+ uint64_t Addend = cast<ConstantSDNode>(LHS.getOperand(1))->getZExtValue();
+ if (OpVT == MVT::i64) {
+ // (a-2^(M-1)) => sext(trunc(a, M), 64)
+ uint64_t ShiftVal = ~Addend + 1;
+ uint64_t CmpVal = ~RHSVal + 1;
+ if (isPowerOf2_64(ShiftVal) && ShiftVal << 1 == CmpVal) {
+ unsigned DestBits = Log2_64(CmpVal);
+ if (DestBits == 8 || DestBits == 16 || DestBits == 32) {
+ SDValue Conv = DAG.getSExtOrTrunc(
+ DAG.getSExtOrTrunc(LHS.getOperand(0), DL,
+ MVT::getIntegerVT(DestBits)),
+ DL, OpVT);
+ return DAG.getSetCC(DL, VT, LHS.getOperand(0), Conv, ISD::SETNE);
+ }
+ }
+ } else if (OpVT == MVT::i32) {
+ if (RHSVal == 0xffffff00 && Addend == 0xffffff80) {
+ SDValue Conv = DAG.getSExtOrTrunc(
+ DAG.getSExtOrTrunc(LHS.getOperand(0), DL, MVT::i8), DL, OpVT);
+ return DAG.getSetCC(DL, VT, LHS.getOperand(0), Conv, ISD::SETNE);
+ }
+ }
+ } else if (LHS.getOpcode() == ISD::SRL &&
+ LHS.getOperand(0).getOpcode() == ISD::ADD &&
+ isa<ConstantSDNode>(LHS.getOperand(1)) &&
+ isa<ConstantSDNode>(LHS.getOperand(0).getOperand(1))) {
+ if (RHSVal == 65535 &&
+ cast<ConstantSDNode>(LHS.getOperand(1))->getZExtValue() == 16 &&
+ cast<ConstantSDNode>(LHS.getOperand(0).getOperand(1))
+ ->getZExtValue() == 0xffff8000) {
+ SDValue Conv = DAG.getSExtOrTrunc(
+ DAG.getSExtOrTrunc(LHS.getOperand(0).getOperand(0), DL, MVT::i16),
+ DL, OpVT);
+ return DAG.getSetCC(DL, VT, LHS.getOperand(0).getOperand(0), Conv,
+ ISD::SETNE);
}
}
}
diff --git a/llvm/test/CodeGen/PowerPC/setcc-to-sub.ll b/llvm/test/CodeGen/PowerPC/setcc-to-sub.ll
index a48458527191c51..1e4d2db2509b257 100644
--- a/llvm/test/CodeGen/PowerPC/setcc-to-sub.ll
+++ b/llvm/test/CodeGen/PowerPC/setcc-to-sub.ll
@@ -134,12 +134,11 @@ entry:
define zeroext i1 @test8(i32 %a) {
; CHECK-LABEL: test8:
; CHECK: # %bb.0: # %entry
-; CHECK-NEXT: addi 3, 3, -32768
-; CHECK-NEXT: lis 4, -1
-; CHECK-NEXT: rlwinm 3, 3, 16, 16, 31
-; CHECK-NEXT: ori 4, 4, 1
-; CHECK-NEXT: add 3, 3, 4
-; CHECK-NEXT: rldicl 3, 3, 1, 63
+; CHECK-NEXT: extsh 4, 3
+; CHECK-NEXT: xor 3, 3, 4
+; CHECK-NEXT: cntlzw 3, 3
+; CHECK-NEXT: srwi 3, 3, 5
+; CHECK-NEXT: xori 3, 3, 1
; CHECK-NEXT: blr
entry:
%0 = add i32 %a, -32768
@@ -150,13 +149,11 @@ entry:
define zeroext i1 @test9(i32 %a) {
; CHECK-LABEL: test9:
; CHECK: # %bb.0: # %entry
-; CHECK-NEXT: lis 4, -256
-; CHECK-NEXT: addi 3, 3, -128
-; CHECK-NEXT: ori 4, 4, 1
-; CHECK-NEXT: clrldi 3, 3, 32
-; CHECK-NEXT: rldic 4, 4, 8, 0
-; CHECK-NEXT: add 3, 3, 4
-; CHECK-NEXT: rldicl 3, 3, 1, 63
+; CHECK-NEXT: extsb 4, 3
+; CHECK-NEXT: xor 3, 3, 4
+; CHECK-NEXT: cntlzw 3, 3
+; CHECK-NEXT: srwi 3, 3, 5
+; CHECK-NEXT: xori 3, 3, 1
; CHECK-NEXT: blr
entry:
%0 = add i32 %a, -128
>From 9bb57d9c55c6625fbe51e7ea3c3464083c1bf4ab Mon Sep 17 00:00:00 2001
From: Qiu Chaofan <qiucofan at cn.ibm.com>
Date: Thu, 30 Nov 2023 10:11:39 +0800
Subject: [PATCH 4/4] Use hex
---
llvm/lib/Target/PowerPC/PPCISelLowering.cpp | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
index 05e940548ff46a0..a15786e31bc12cc 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -14441,7 +14441,6 @@ SDValue PPCTargetLowering::combineSetCC(SDNode *N, DAGCombinerInfo &DCI) const {
if (LHS.getOpcode() == ISD::ADD && isa<ConstantSDNode>(LHS.getOperand(1))) {
uint64_t Addend = cast<ConstantSDNode>(LHS.getOperand(1))->getZExtValue();
if (OpVT == MVT::i64) {
- // (a-2^(M-1)) => sext(trunc(a, M), 64)
uint64_t ShiftVal = ~Addend + 1;
uint64_t CmpVal = ~RHSVal + 1;
if (isPowerOf2_64(ShiftVal) && ShiftVal << 1 == CmpVal) {
@@ -14465,7 +14464,7 @@ SDValue PPCTargetLowering::combineSetCC(SDNode *N, DAGCombinerInfo &DCI) const {
LHS.getOperand(0).getOpcode() == ISD::ADD &&
isa<ConstantSDNode>(LHS.getOperand(1)) &&
isa<ConstantSDNode>(LHS.getOperand(0).getOperand(1))) {
- if (RHSVal == 65535 &&
+ if (RHSVal == 0xffff &&
cast<ConstantSDNode>(LHS.getOperand(1))->getZExtValue() == 16 &&
cast<ConstantSDNode>(LHS.getOperand(0).getOperand(1))
->getZExtValue() == 0xffff8000) {
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