[llvm-branch-commits] [llvm] 2d60429 - [SelectionDAGBuilder] Add SPF_NABS support to visitSelect
Craig Topper via llvm-branch-commits
llvm-branch-commits at lists.llvm.org
Wed Nov 25 15:08:10 PST 2020
Author: Craig Topper
Date: 2020-11-25T14:54:26-08:00
New Revision: 2d6042937b04eef00672b5c4ce623bf8f7b9a201
URL: https://github.com/llvm/llvm-project/commit/2d6042937b04eef00672b5c4ce623bf8f7b9a201
DIFF: https://github.com/llvm/llvm-project/commit/2d6042937b04eef00672b5c4ce623bf8f7b9a201.diff
LOG: [SelectionDAGBuilder] Add SPF_NABS support to visitSelect
We currently don't match this which limits the effectiveness of D91120 until
InstCombine starts canonicalizing to llvm.abs. This should be easy to remove
if/when we remove the SPF_ABS handling.
Differential Revision: https://reviews.llvm.org/D92118
Added:
Modified:
llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
llvm/test/CodeGen/PowerPC/select.ll
llvm/test/CodeGen/RISCV/neg-abs.ll
Removed:
################################################################################
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 959bb52cb223..ca4c2ca2a846 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -3131,6 +3131,7 @@ void SelectionDAGBuilder::visitSelect(const User &I) {
Cond.getValueType().isVector() ? ISD::VSELECT : ISD::SELECT;
bool IsUnaryAbs = false;
+ bool Negate = false;
SDNodeFlags Flags;
if (auto *FPOp = dyn_cast<FPMathOperator>(&I))
@@ -3195,12 +3196,13 @@ void SelectionDAGBuilder::visitSelect(const User &I) {
break;
}
break;
+ case SPF_NABS:
+ Negate = true;
+ LLVM_FALLTHROUGH;
case SPF_ABS:
IsUnaryAbs = true;
Opc = ISD::ABS;
break;
- case SPF_NABS:
- // TODO: we need to produce sub(0, abs(X)).
default: break;
}
@@ -3227,10 +3229,13 @@ void SelectionDAGBuilder::visitSelect(const User &I) {
if (IsUnaryAbs) {
for (unsigned i = 0; i != NumValues; ++i) {
+ SDLoc dl = getCurSDLoc();
+ EVT VT = LHSVal.getNode()->getValueType(LHSVal.getResNo() + i);
Values[i] =
- DAG.getNode(OpCode, getCurSDLoc(),
- LHSVal.getNode()->getValueType(LHSVal.getResNo() + i),
- SDValue(LHSVal.getNode(), LHSVal.getResNo() + i));
+ DAG.getNode(OpCode, dl, VT, LHSVal.getValue(LHSVal.getResNo() + i));
+ if (Negate)
+ Values[i] = DAG.getNode(ISD::SUB, dl, VT, DAG.getConstant(0, dl, VT),
+ Values[i]);
}
} else {
for (unsigned i = 0; i != NumValues; ++i) {
diff --git a/llvm/test/CodeGen/PowerPC/select.ll b/llvm/test/CodeGen/PowerPC/select.ll
index 1b53724079c7..bbbffe4d62cd 100644
--- a/llvm/test/CodeGen/PowerPC/select.ll
+++ b/llvm/test/CodeGen/PowerPC/select.ll
@@ -111,26 +111,18 @@ define i64 @f3(i64 %x, i64 %y) {
define i64 @f4(i64 %x) {
; CHECK-LE-LABEL: f4:
; CHECK-LE: # %bb.0:
-; CHECK-LE-NEXT: neg r4, r3
-; CHECK-LE-NEXT: cmpdi r3, 0
-; CHECK-LE-NEXT: iselgt r3, r4, r3
+; CHECK-LE-NEXT: sradi r4, r3, 63
+; CHECK-LE-NEXT: xor r3, r3, r4
+; CHECK-LE-NEXT: sub r3, r4, r3
; CHECK-LE-NEXT: blr
;
; CHECK-32-LABEL: f4:
; CHECK-32: # %bb.0:
-; CHECK-32-NEXT: cmplwi r3, 0
-; CHECK-32-NEXT: cmpwi cr1, r3, 0
-; CHECK-32-NEXT: crandc 4*cr5+lt, 4*cr1+gt, eq
-; CHECK-32-NEXT: cmpwi cr1, r4, 0
-; CHECK-32-NEXT: subfic r5, r4, 0
-; CHECK-32-NEXT: crandc 4*cr5+gt, eq, 4*cr1+eq
-; CHECK-32-NEXT: cror 4*cr5+lt, 4*cr5+gt, 4*cr5+lt
-; CHECK-32-NEXT: subfze r6, r3
-; CHECK-32-NEXT: bc 12, 4*cr5+lt, .LBB4_1
-; CHECK-32-NEXT: blr
-; CHECK-32-NEXT: .LBB4_1:
-; CHECK-32-NEXT: addi r3, r6, 0
-; CHECK-32-NEXT: addi r4, r5, 0
+; CHECK-32-NEXT: srawi r5, r3, 31
+; CHECK-32-NEXT: xor r4, r4, r5
+; CHECK-32-NEXT: xor r3, r3, r5
+; CHECK-32-NEXT: subc r4, r5, r4
+; CHECK-32-NEXT: subfe r3, r3, r5
; CHECK-32-NEXT: blr
%c = icmp sgt i64 %x, 0
%x.neg = sub i64 0, %x
@@ -166,20 +158,18 @@ define i64 @f4_sge_0(i64 %x) {
define i64 @f4_slt_0(i64 %x) {
; CHECK-LE-LABEL: f4_slt_0:
; CHECK-LE: # %bb.0:
-; CHECK-LE-NEXT: neg r4, r3
-; CHECK-LE-NEXT: cmpdi r3, 0
-; CHECK-LE-NEXT: isellt r3, r3, r4
+; CHECK-LE-NEXT: sradi r4, r3, 63
+; CHECK-LE-NEXT: xor r3, r3, r4
+; CHECK-LE-NEXT: sub r3, r4, r3
; CHECK-LE-NEXT: blr
;
; CHECK-32-LABEL: f4_slt_0:
; CHECK-32: # %bb.0:
-; CHECK-32-NEXT: subfic r5, r4, 0
-; CHECK-32-NEXT: subfze r6, r3
-; CHECK-32-NEXT: cmpwi r3, 0
-; CHECK-32-NEXT: bclr 12, lt, 0
-; CHECK-32-NEXT: # %bb.1:
-; CHECK-32-NEXT: ori r3, r6, 0
-; CHECK-32-NEXT: ori r4, r5, 0
+; CHECK-32-NEXT: srawi r5, r3, 31
+; CHECK-32-NEXT: xor r4, r4, r5
+; CHECK-32-NEXT: xor r3, r3, r5
+; CHECK-32-NEXT: subc r4, r5, r4
+; CHECK-32-NEXT: subfe r3, r3, r5
; CHECK-32-NEXT: blr
%c = icmp slt i64 %x, 0
%x.neg = sub i64 0, %x
@@ -219,21 +209,18 @@ define i64 @f4_sle_0(i64 %x) {
define i64 @f4_sgt_m1(i64 %x) {
; CHECK-LE-LABEL: f4_sgt_m1:
; CHECK-LE: # %bb.0:
-; CHECK-LE-NEXT: neg r4, r3
-; CHECK-LE-NEXT: cmpdi r3, -1
-; CHECK-LE-NEXT: iselgt r3, r4, r3
+; CHECK-LE-NEXT: sradi r4, r3, 63
+; CHECK-LE-NEXT: xor r3, r3, r4
+; CHECK-LE-NEXT: sub r3, r4, r3
; CHECK-LE-NEXT: blr
;
; CHECK-32-LABEL: f4_sgt_m1:
; CHECK-32: # %bb.0:
-; CHECK-32-NEXT: subfic r5, r4, 0
-; CHECK-32-NEXT: subfze r6, r3
-; CHECK-32-NEXT: cmpwi r3, -1
-; CHECK-32-NEXT: bc 12, gt, .LBB8_1
-; CHECK-32-NEXT: blr
-; CHECK-32-NEXT: .LBB8_1:
-; CHECK-32-NEXT: addi r3, r6, 0
-; CHECK-32-NEXT: addi r4, r5, 0
+; CHECK-32-NEXT: srawi r5, r3, 31
+; CHECK-32-NEXT: xor r4, r4, r5
+; CHECK-32-NEXT: xor r3, r3, r5
+; CHECK-32-NEXT: subc r4, r5, r4
+; CHECK-32-NEXT: subfe r3, r3, r5
; CHECK-32-NEXT: blr
%c = icmp sgt i64 %x, -1
%x.neg = sub i64 0, %x
diff --git a/llvm/test/CodeGen/RISCV/neg-abs.ll b/llvm/test/CodeGen/RISCV/neg-abs.ll
index 10290a0f8b89..b5e5d2ae3149 100644
--- a/llvm/test/CodeGen/RISCV/neg-abs.ll
+++ b/llvm/test/CodeGen/RISCV/neg-abs.ll
@@ -27,19 +27,16 @@ define i32 @neg_abs32(i32 %x) {
define i32 @select_neg_abs32(i32 %x) {
; RV32-LABEL: select_neg_abs32:
; RV32: # %bb.0:
-; RV32-NEXT: bltz a0, .LBB1_2
-; RV32-NEXT: # %bb.1:
-; RV32-NEXT: neg a0, a0
-; RV32-NEXT: .LBB1_2:
+; RV32-NEXT: srai a1, a0, 31
+; RV32-NEXT: xor a0, a0, a1
+; RV32-NEXT: sub a0, a1, a0
; RV32-NEXT: ret
;
; RV64-LABEL: select_neg_abs32:
; RV64: # %bb.0:
-; RV64-NEXT: sext.w a1, a0
-; RV64-NEXT: bltz a1, .LBB1_2
-; RV64-NEXT: # %bb.1:
-; RV64-NEXT: negw a0, a0
-; RV64-NEXT: .LBB1_2:
+; RV64-NEXT: sraiw a1, a0, 31
+; RV64-NEXT: xor a0, a0, a1
+; RV64-NEXT: subw a0, a1, a0
; RV64-NEXT: ret
%1 = icmp slt i32 %x, 0
%2 = sub nsw i32 0, %x
@@ -73,21 +70,20 @@ define i64 @neg_abs64(i64 %x) {
define i64 @select_neg_abs64(i64 %x) {
; RV32-LABEL: select_neg_abs64:
; RV32: # %bb.0:
-; RV32-NEXT: bltz a1, .LBB3_2
-; RV32-NEXT: # %bb.1:
-; RV32-NEXT: snez a2, a0
-; RV32-NEXT: add a1, a1, a2
-; RV32-NEXT: neg a1, a1
-; RV32-NEXT: neg a0, a0
-; RV32-NEXT: .LBB3_2:
+; RV32-NEXT: srai a2, a1, 31
+; RV32-NEXT: xor a0, a0, a2
+; RV32-NEXT: sltu a3, a2, a0
+; RV32-NEXT: xor a1, a1, a2
+; RV32-NEXT: sub a1, a2, a1
+; RV32-NEXT: sub a1, a1, a3
+; RV32-NEXT: sub a0, a2, a0
; RV32-NEXT: ret
;
; RV64-LABEL: select_neg_abs64:
; RV64: # %bb.0:
-; RV64-NEXT: bltz a0, .LBB3_2
-; RV64-NEXT: # %bb.1:
-; RV64-NEXT: neg a0, a0
-; RV64-NEXT: .LBB3_2:
+; RV64-NEXT: srai a1, a0, 63
+; RV64-NEXT: xor a0, a0, a1
+; RV64-NEXT: sub a0, a1, a0
; RV64-NEXT: ret
%1 = icmp slt i64 %x, 0
%2 = sub nsw i64 0, %x
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