third_party/llvm-7.0/llvm/test/Analysis/ScalarEvolution/min-max-exprs.ll

; RUN: opt -scalar-evolution -analyze < %s | FileCheck %s
;
; This checks if the min and max expressions are properly recognized by
; ScalarEvolution even though they the ICmpInst and SelectInst have different
; types.
;
;    #define max(a, b) (a > b ? a : b)
;    #define min(a, b) (a < b ? a : b)
;
;    void f(int *A, int N) {
;      for (int i = 0; i < N; i++) {
;        A[max(0, i - 3)] = A[min(N, i + 3)] * 2;
;      }
;    }
;
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"

define void @f(i32* %A, i32 %N) {
bb:
  br label %bb1

bb1:                                              ; preds = %bb2, %bb
  %i.0 = phi i32 [ 0, %bb ], [ %tmp23, %bb2 ]
  %i.0.1 = sext i32 %i.0 to i64
  %tmp = icmp slt i32 %i.0, %N
  br i1 %tmp, label %bb2, label %bb24

bb2:                                              ; preds = %bb1
  %tmp3 = add nuw nsw i32 %i.0, 3
  %tmp4 = icmp slt i32 %tmp3, %N
  %tmp5 = sext i32 %tmp3 to i64
  %tmp6 = sext i32 %N to i64
  %tmp9 = select i1 %tmp4, i64 %tmp5, i64 %tmp6
;                  min(N, i+3)
; CHECK:           select i1 %tmp4, i64 %tmp5, i64 %tmp6
; CHECK-NEXT:  --> (-1 + (-1 * ((-1 + (-1 * (sext i32 {3,+,1}<nuw><%bb1> to i64))<nsw>)<nsw> smax (-1 + (-1 * (sext i32 %N to i64))<nsw>)<nsw>))<nsw>)<nsw>
  %tmp11 = getelementptr inbounds i32, i32* %A, i64 %tmp9
  %tmp12 = load i32, i32* %tmp11, align 4
  %tmp13 = shl nsw i32 %tmp12, 1
  %tmp14 = icmp sge i32 3, %i.0
  %tmp17 = add nsw i64 %i.0.1, -3
  %tmp19 = select i1 %tmp14, i64 0, i64 %tmp17
;                  max(0, i - 3)
; CHECK:           select i1 %tmp14, i64 0, i64 %tmp17
; CHECK-NEXT: -->  (-3 + (3 smax {0,+,1}<nuw><nsw><%bb1>))
  %tmp21 = getelementptr inbounds i32, i32* %A, i64 %tmp19
  store i32 %tmp13, i32* %tmp21, align 4
  %tmp23 = add nuw nsw i32 %i.0, 1
  br label %bb1

bb24:                                             ; preds = %bb1
  ret void
}