[clang] [DAGCombine] Fold setcc_eq infinity into is.fpclass (PR #67829)
Qiu Chaofan via cfe-commits
cfe-commits at lists.llvm.org
Thu Oct 26 01:31:39 PDT 2023
https://github.com/ecnelises updated https://github.com/llvm/llvm-project/pull/67829
>From 45906e0ec45c9302f4d9af10b94276c7f7185fef Mon Sep 17 00:00:00 2001
From: Qiu Chaofan <qiucofan at cn.ibm.com>
Date: Sat, 30 Sep 2023 00:21:14 +0800
Subject: [PATCH 1/2] [DAGCombine] Fold setcc_eq infinity into is.fpclass
---
.../CodeGen/SelectionDAG/TargetLowering.cpp | 14 +++++
llvm/test/CodeGen/PowerPC/fp-classify.ll | 53 +++++++------------
llvm/test/CodeGen/PowerPC/is_fpclass.ll | 7 +--
3 files changed, 34 insertions(+), 40 deletions(-)
diff --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index c0e88051dc427f1..ec5591a3528eab8 100644
--- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -5064,6 +5064,20 @@ SDValue TargetLowering::SimplifySetCC(EVT VT, SDValue N0, SDValue N1,
}
}
+ if (isOperationLegalOrCustom(ISD::IS_FPCLASS, N0.getValueType()) &&
+ !isFPImmLegal(CFP->getValueAPF(), CFP->getValueType(0))) {
+ bool IsFabs = N0.getOpcode() == ISD::FABS;
+ SDValue Op = IsFabs ? N0.getOperand(0) : N0;
+ if ((Cond == ISD::SETOEQ || Cond == ISD::SETUEQ) && CFP->isInfinity()) {
+ FPClassTest Flag = CFP->isNegative() ? (IsFabs ? fcNone : fcNegInf)
+ : (IsFabs ? fcInf : fcPosInf);
+ if (Cond == ISD::SETUEQ)
+ Flag |= fcNan;
+ return DAG.getNode(ISD::IS_FPCLASS, dl, VT, Op,
+ DAG.getTargetConstant(Flag, dl, MVT::i32));
+ }
+ }
+
// If the condition is not legal, see if we can find an equivalent one
// which is legal.
if (!isCondCodeLegal(Cond, N0.getSimpleValueType())) {
diff --git a/llvm/test/CodeGen/PowerPC/fp-classify.ll b/llvm/test/CodeGen/PowerPC/fp-classify.ll
index 26cde62071224fb..7de35b880a5d9cf 100644
--- a/llvm/test/CodeGen/PowerPC/fp-classify.ll
+++ b/llvm/test/CodeGen/PowerPC/fp-classify.ll
@@ -18,12 +18,9 @@ define zeroext i1 @abs_isinff(float %x) {
;
; P9-LABEL: abs_isinff:
; P9: # %bb.0: # %entry
-; P9-NEXT: addis 3, 2, .LCPI0_0 at toc@ha
-; P9-NEXT: xsabsdp 0, 1
-; P9-NEXT: li 4, 1
-; P9-NEXT: lfs 1, .LCPI0_0 at toc@l(3)
+; P9-NEXT: xststdcsp 0, 1, 48
; P9-NEXT: li 3, 0
-; P9-NEXT: fcmpu 0, 0, 1
+; P9-NEXT: li 4, 1
; P9-NEXT: iseleq 3, 4, 3
; P9-NEXT: blr
entry:
@@ -46,12 +43,9 @@ define zeroext i1 @abs_isinf(double %x) {
;
; P9-LABEL: abs_isinf:
; P9: # %bb.0: # %entry
-; P9-NEXT: addis 3, 2, .LCPI1_0 at toc@ha
-; P9-NEXT: xsabsdp 0, 1
-; P9-NEXT: li 4, 1
-; P9-NEXT: lfs 1, .LCPI1_0 at toc@l(3)
+; P9-NEXT: xststdcdp 0, 1, 48
; P9-NEXT: li 3, 0
-; P9-NEXT: fcmpu 0, 0, 1
+; P9-NEXT: li 4, 1
; P9-NEXT: iseleq 3, 4, 3
; P9-NEXT: blr
entry:
@@ -91,13 +85,9 @@ define zeroext i1 @abs_isinfq(fp128 %x) {
;
; P9-LABEL: abs_isinfq:
; P9: # %bb.0: # %entry
-; P9-NEXT: addis 3, 2, .LCPI2_0 at toc@ha
-; P9-NEXT: xsabsqp 2, 2
-; P9-NEXT: li 4, 1
-; P9-NEXT: addi 3, 3, .LCPI2_0 at toc@l
-; P9-NEXT: lxv 35, 0(3)
+; P9-NEXT: xststdcqp 0, 2, 48
; P9-NEXT: li 3, 0
-; P9-NEXT: xscmpuqp 0, 2, 3
+; P9-NEXT: li 4, 1
; P9-NEXT: iseleq 3, 4, 3
; P9-NEXT: blr
entry:
@@ -119,12 +109,10 @@ define zeroext i1 @abs_isinfornanf(float %x) {
;
; P9-LABEL: abs_isinfornanf:
; P9: # %bb.0: # %entry
-; P9-NEXT: addis 3, 2, .LCPI3_0 at toc@ha
-; P9-NEXT: xsabsdp 0, 1
-; P9-NEXT: lfs 1, .LCPI3_0 at toc@l(3)
-; P9-NEXT: li 3, 1
-; P9-NEXT: fcmpu 0, 0, 1
-; P9-NEXT: isellt 3, 0, 3
+; P9-NEXT: xststdcsp 0, 1, 112
+; P9-NEXT: li 3, 0
+; P9-NEXT: li 4, 1
+; P9-NEXT: iseleq 3, 4, 3
; P9-NEXT: blr
entry:
%0 = tail call float @llvm.fabs.f32(float %x)
@@ -145,12 +133,10 @@ define zeroext i1 @abs_isinfornan(double %x) {
;
; P9-LABEL: abs_isinfornan:
; P9: # %bb.0: # %entry
-; P9-NEXT: addis 3, 2, .LCPI4_0 at toc@ha
-; P9-NEXT: xsabsdp 0, 1
-; P9-NEXT: lfs 1, .LCPI4_0 at toc@l(3)
-; P9-NEXT: li 3, 1
-; P9-NEXT: fcmpu 0, 0, 1
-; P9-NEXT: isellt 3, 0, 3
+; P9-NEXT: xststdcdp 0, 1, 112
+; P9-NEXT: li 3, 0
+; P9-NEXT: li 4, 1
+; P9-NEXT: iseleq 3, 4, 3
; P9-NEXT: blr
entry:
%0 = tail call double @llvm.fabs.f64(double %x)
@@ -212,13 +198,10 @@ define zeroext i1 @abs_isinfornanq(fp128 %x) {
;
; P9-LABEL: abs_isinfornanq:
; P9: # %bb.0: # %entry
-; P9-NEXT: addis 3, 2, .LCPI5_0 at toc@ha
-; P9-NEXT: xsabsqp 2, 2
-; P9-NEXT: addi 3, 3, .LCPI5_0 at toc@l
-; P9-NEXT: lxv 35, 0(3)
-; P9-NEXT: li 3, 1
-; P9-NEXT: xscmpuqp 0, 2, 3
-; P9-NEXT: isellt 3, 0, 3
+; P9-NEXT: xststdcqp 0, 2, 112
+; P9-NEXT: li 3, 0
+; P9-NEXT: li 4, 1
+; P9-NEXT: iseleq 3, 4, 3
; P9-NEXT: blr
entry:
%0 = tail call fp128 @llvm.fabs.f128(fp128 %x)
diff --git a/llvm/test/CodeGen/PowerPC/is_fpclass.ll b/llvm/test/CodeGen/PowerPC/is_fpclass.ll
index 1ba4749d7437df5..57f457553a54070 100644
--- a/llvm/test/CodeGen/PowerPC/is_fpclass.ll
+++ b/llvm/test/CodeGen/PowerPC/is_fpclass.ll
@@ -117,12 +117,9 @@ define i1 @isinf_float(float %x) nounwind {
define i1 @isinf_ppc_fp128(ppc_fp128 %x) nounwind {
; CHECK-LABEL: isinf_ppc_fp128:
; CHECK: # %bb.0:
-; CHECK-NEXT: addis 3, 2, .LCPI9_0 at toc@ha
-; CHECK-NEXT: xsabsdp 0, 1
-; CHECK-NEXT: li 4, 1
-; CHECK-NEXT: lfs 1, .LCPI9_0 at toc@l(3)
+; CHECK-NEXT: xststdcdp 0, 1, 48
; CHECK-NEXT: li 3, 0
-; CHECK-NEXT: fcmpu 0, 0, 1
+; CHECK-NEXT: li 4, 1
; CHECK-NEXT: iseleq 3, 4, 3
; CHECK-NEXT: blr
%1 = call i1 @llvm.is.fpclass.ppcf128(ppc_fp128 %x, i32 516) ; 0x204 = "inf"
>From 498be49636716b381d4b3c2b2b861c31ffff56fc Mon Sep 17 00:00:00 2001
From: Qiu Chaofan <qiucofan at cn.ibm.com>
Date: Thu, 26 Oct 2023 16:30:57 +0800
Subject: [PATCH 2/2] Add comments
---
llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp | 1 +
1 file changed, 1 insertion(+)
diff --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index 906e5a52297f31c..ba67092c3177636 100644
--- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -5064,6 +5064,7 @@ SDValue TargetLowering::SimplifySetCC(EVT VT, SDValue N0, SDValue N1,
}
}
+ // setueq/setoeq X, (fabs Inf) -> is_fpclass X, fcInf
if (isOperationLegalOrCustom(ISD::IS_FPCLASS, N0.getValueType()) &&
!isFPImmLegal(CFP->getValueAPF(), CFP->getValueType(0))) {
bool IsFabs = N0.getOpcode() == ISD::FABS;
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