[InstCombine] Fold its select user into select for float type

The pattern matcher checks the operand of the select is also a select
instruction, so the condition and the selection type must be both scalar
nor both vector types.

Author: vfdff

llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp

@@ -515,20 +515,17 @@ static bool simplifySeqSelectWithSameCond(SelectInst &SI,
     Value *RepOp = OpIndex == 1 ? ConstantInt::getTrue(CondType)
                                 : ConstantInt::getFalse(CondType);
     SelectInst *SINext = &SI;
-    Type *SelType = SINext->getType();
     Value *ValOp = SINext->getOperand(OpIndex);
     Value *CondNext;
     while (match(ValOp, m_Select(m_Value(CondNext), m_Value(), m_Value()))) {
-      if (CondNext == CondVal && SelType->isIntOrIntVectorTy() &&
-          CondType->isVectorTy() == SelType->isVectorTy())
+      if (CondNext == CondVal)
         if (Value *S = simplifyWithOpReplaced(ValOp, CondVal, RepOp, SQ,
                                               /* AllowRefinement */ true)) {
           IC.replaceOperand(*SINext, OpIndex, S);
           return true;
         }
 
       SINext = cast<SelectInst>(ValOp);
-      SelType = SINext->getType();
       ValOp = SINext->getOperand(OpIndex);
     }
     return false;

llvm/test/Transforms/InstCombine/select.ll

@@ -3734,6 +3734,21 @@ define i32 @sequence_select_with_same_cond_true (i1 %c1, i1 %c2){
   ret i32 %s3
 }
 
+; https://alive2.llvm.org/ce/z/3Uaiis
+define double @sequence_select_with_same_cond_double(double %a, i1 %c1, i1 %c2, double %r1, double %r2){
+; CHECK-LABEL: @sequence_select_with_same_cond_double(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[S2:%.*]] = select i1 [[C2:%.*]], double 1.000000e+00, double 2.000000e+00
+; CHECK-NEXT:    [[S3:%.*]] = select i1 [[C1:%.*]], double [[S2]], double 3.000000e+00
+; CHECK-NEXT:    ret double [[S3]]
+;
+entry:
+  %s1 = select i1 %c1, double 1.0, double 0.0
+  %s2 = select i1 %c2, double %s1, double 2.0
+  %s3 = select i1 %c1, double %s2, double 3.0
+  ret double %s3
+}
+
 declare void @use32(i32)
 
 define i32 @sequence_select_with_same_cond_extra_use (i1 %c1, i1 %c2){