[RISCV] Refine cost on Min/Max reduction with i1 type (#79401)

It is split off from #77342.
InstCombine transform min/max reduction with i1 into arithmetic
reduction,
so this patch reuses the cost logic in arithmetic reduction cost
function.

Author: arcbbb

llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp

@@ -936,10 +936,15 @@ RISCVTTIImpl::getMinMaxReductionCost(Intrinsic::ID IID, VectorType *Ty,
     return BaseT::getMinMaxReductionCost(IID, Ty, FMF, CostKind);
 
   std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(Ty);
-  if (Ty->getElementType()->isIntegerTy(1))
-    // vcpop sequences, see vreduction-mask.ll.  umax, smin actually only
-    // cost 2, but we don't have enough info here so we slightly over cost.
-    return (LT.first - 1) + 3;
+  if (Ty->getElementType()->isIntegerTy(1)) {
+    // SelectionDAGBuilder does following transforms:
+    //   vector_reduce_{smin,umax}(<n x i1>) --> vector_reduce_or(<n x i1>)
+    //   vector_reduce_{smax,umin}(<n x i1>) --> vector_reduce_and(<n x i1>)
+    if (IID == Intrinsic::umax || IID == Intrinsic::smin)
+      return getArithmeticReductionCost(Instruction::Or, Ty, FMF, CostKind);
+    else
+      return getArithmeticReductionCost(Instruction::And, Ty, FMF, CostKind);
+  }
 
   // IR Reduction is composed by two vmv and one rvv reduction instruction.
   InstructionCost BaseCost = 2;

llvm/test/Analysis/CostModel/RISCV/reduce-max.ll

@@ -6,25 +6,25 @@
 
 define i32 @reduce_umin_i1(i32 %arg) {
 ; CHECK-LABEL: 'reduce_umin_i1'
-; CHECK-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %V1 = call i1 @llvm.vector.reduce.umax.v1i1(<1 x i1> undef)
-; CHECK-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %V2 = call i1 @llvm.vector.reduce.umax.v2i1(<2 x i1> undef)
-; CHECK-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %V4 = call i1 @llvm.vector.reduce.umax.v4i1(<4 x i1> undef)
-; CHECK-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %V8 = call i1 @llvm.vector.reduce.umax.v8i1(<8 x i1> undef)
-; CHECK-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %V16 = call i1 @llvm.vector.reduce.umax.v16i1(<16 x i1> undef)
-; CHECK-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %V32 = call i1 @llvm.vector.reduce.umax.v32i1(<32 x i1> undef)
-; CHECK-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %V64 = call i1 @llvm.vector.reduce.umax.v64i1(<64 x i1> undef)
-; CHECK-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %V128 = call i1 @llvm.vector.reduce.umax.v128i1(<128 x i1> undef)
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %V1 = call i1 @llvm.vector.reduce.umax.v1i1(<1 x i1> undef)
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %V2 = call i1 @llvm.vector.reduce.umax.v2i1(<2 x i1> undef)
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %V4 = call i1 @llvm.vector.reduce.umax.v4i1(<4 x i1> undef)
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %V8 = call i1 @llvm.vector.reduce.umax.v8i1(<8 x i1> undef)
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %V16 = call i1 @llvm.vector.reduce.umax.v16i1(<16 x i1> undef)
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %V32 = call i1 @llvm.vector.reduce.umax.v32i1(<32 x i1> undef)
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %V64 = call i1 @llvm.vector.reduce.umax.v64i1(<64 x i1> undef)
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %V128 = call i1 @llvm.vector.reduce.umax.v128i1(<128 x i1> undef)
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: ret i32 undef
 ;
 ; SIZE-LABEL: 'reduce_umin_i1'
-; SIZE-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %V1 = call i1 @llvm.vector.reduce.umax.v1i1(<1 x i1> undef)
-; SIZE-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %V2 = call i1 @llvm.vector.reduce.umax.v2i1(<2 x i1> undef)
-; SIZE-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %V4 = call i1 @llvm.vector.reduce.umax.v4i1(<4 x i1> undef)
-; SIZE-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %V8 = call i1 @llvm.vector.reduce.umax.v8i1(<8 x i1> undef)
-; SIZE-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %V16 = call i1 @llvm.vector.reduce.umax.v16i1(<16 x i1> undef)
-; SIZE-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %V32 = call i1 @llvm.vector.reduce.umax.v32i1(<32 x i1> undef)
-; SIZE-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %V64 = call i1 @llvm.vector.reduce.umax.v64i1(<64 x i1> undef)
-; SIZE-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %V128 = call i1 @llvm.vector.reduce.umax.v128i1(<128 x i1> undef)
+; SIZE-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %V1 = call i1 @llvm.vector.reduce.umax.v1i1(<1 x i1> undef)
+; SIZE-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %V2 = call i1 @llvm.vector.reduce.umax.v2i1(<2 x i1> undef)
+; SIZE-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %V4 = call i1 @llvm.vector.reduce.umax.v4i1(<4 x i1> undef)
+; SIZE-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %V8 = call i1 @llvm.vector.reduce.umax.v8i1(<8 x i1> undef)
+; SIZE-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %V16 = call i1 @llvm.vector.reduce.umax.v16i1(<16 x i1> undef)
+; SIZE-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %V32 = call i1 @llvm.vector.reduce.umax.v32i1(<32 x i1> undef)
+; SIZE-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %V64 = call i1 @llvm.vector.reduce.umax.v64i1(<64 x i1> undef)
+; SIZE-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %V128 = call i1 @llvm.vector.reduce.umax.v128i1(<128 x i1> undef)
 ; SIZE-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: ret i32 undef
 ;
   %V1   = call i1 @llvm.vector.reduce.umax.v1i1(<1 x i1> undef)

llvm/test/Analysis/CostModel/RISCV/reduce-min.ll

@@ -176,25 +176,25 @@ define i32 @reduce_umin_i64(i32 %arg) {
 
 define i32 @reduce_smin_i1(i32 %arg) {
 ; CHECK-LABEL: 'reduce_smin_i1'
-; CHECK-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %V1 = call i1 @llvm.vector.reduce.smin.v1i1(<1 x i1> undef)
-; CHECK-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %V2 = call i1 @llvm.vector.reduce.smin.v2i1(<2 x i1> undef)
-; CHECK-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %V4 = call i1 @llvm.vector.reduce.smin.v4i1(<4 x i1> undef)
-; CHECK-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %V8 = call i1 @llvm.vector.reduce.smin.v8i1(<8 x i1> undef)
-; CHECK-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %V16 = call i1 @llvm.vector.reduce.smin.v16i1(<16 x i1> undef)
-; CHECK-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %V32 = call i1 @llvm.vector.reduce.smin.v32i1(<32 x i1> undef)
-; CHECK-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %V64 = call i1 @llvm.vector.reduce.smin.v64i1(<64 x i1> undef)
-; CHECK-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %V128 = call i1 @llvm.vector.reduce.smin.v128i1(<128 x i1> undef)
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %V1 = call i1 @llvm.vector.reduce.smin.v1i1(<1 x i1> undef)
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %V2 = call i1 @llvm.vector.reduce.smin.v2i1(<2 x i1> undef)
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %V4 = call i1 @llvm.vector.reduce.smin.v4i1(<4 x i1> undef)
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %V8 = call i1 @llvm.vector.reduce.smin.v8i1(<8 x i1> undef)
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %V16 = call i1 @llvm.vector.reduce.smin.v16i1(<16 x i1> undef)
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %V32 = call i1 @llvm.vector.reduce.smin.v32i1(<32 x i1> undef)
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %V64 = call i1 @llvm.vector.reduce.smin.v64i1(<64 x i1> undef)
+; CHECK-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %V128 = call i1 @llvm.vector.reduce.smin.v128i1(<128 x i1> undef)
 ; CHECK-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: ret i32 undef
 ;
 ; SIZE-LABEL: 'reduce_smin_i1'
-; SIZE-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %V1 = call i1 @llvm.vector.reduce.smin.v1i1(<1 x i1> undef)
-; SIZE-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %V2 = call i1 @llvm.vector.reduce.smin.v2i1(<2 x i1> undef)
-; SIZE-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %V4 = call i1 @llvm.vector.reduce.smin.v4i1(<4 x i1> undef)
-; SIZE-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %V8 = call i1 @llvm.vector.reduce.smin.v8i1(<8 x i1> undef)
-; SIZE-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %V16 = call i1 @llvm.vector.reduce.smin.v16i1(<16 x i1> undef)
-; SIZE-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %V32 = call i1 @llvm.vector.reduce.smin.v32i1(<32 x i1> undef)
-; SIZE-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %V64 = call i1 @llvm.vector.reduce.smin.v64i1(<64 x i1> undef)
-; SIZE-NEXT:  Cost Model: Found an estimated cost of 3 for instruction: %V128 = call i1 @llvm.vector.reduce.smin.v128i1(<128 x i1> undef)
+; SIZE-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %V1 = call i1 @llvm.vector.reduce.smin.v1i1(<1 x i1> undef)
+; SIZE-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %V2 = call i1 @llvm.vector.reduce.smin.v2i1(<2 x i1> undef)
+; SIZE-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %V4 = call i1 @llvm.vector.reduce.smin.v4i1(<4 x i1> undef)
+; SIZE-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %V8 = call i1 @llvm.vector.reduce.smin.v8i1(<8 x i1> undef)
+; SIZE-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %V16 = call i1 @llvm.vector.reduce.smin.v16i1(<16 x i1> undef)
+; SIZE-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %V32 = call i1 @llvm.vector.reduce.smin.v32i1(<32 x i1> undef)
+; SIZE-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %V64 = call i1 @llvm.vector.reduce.smin.v64i1(<64 x i1> undef)
+; SIZE-NEXT:  Cost Model: Found an estimated cost of 2 for instruction: %V128 = call i1 @llvm.vector.reduce.smin.v128i1(<128 x i1> undef)
 ; SIZE-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: ret i32 undef
 ;
   %V1   = call i1 @llvm.vector.reduce.smin.v1i1(<1 x i1> undef)