; RUN: opt < %s -S -loop-unroll -unroll-max-iteration-count-to-analyze=100 -unroll-dynamic-cost-savings-discount=1000 -unroll-threshold=10 -unroll-percent-dynamic-cost-saved-threshold=50 | FileCheck %s target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128" @known_constant = internal unnamed_addr constant [10 x i32] [i32 0, i32 1, i32 0, i32 1, i32 0, i32 1, i32 0, i32 1, i32 0, i32 1], align 16 ; We should be able to propagate constant data through different types of ; casts. For example, in this test we have a load, which becomes constant after ; unrolling, which then is truncated to i8. Obviously, truncated value is also a ; constant, which can be used in the further simplifications. ; ; We expect this loop to be unrolled, because in this case load would become ; constant, which is 0 in many cases, and which, in its turn, helps to simplify ; following multiplication and addition. In total, unrolling should help to ; optimize ~60% of all instructions in this case. ; ; CHECK-LABEL: @const_load_trunc ; CHECK-NOT: br i1 ; CHECK: ret i8 % define i8 @const_load_trunc(i32* noalias nocapture readonly %src) { entry: br label %loop loop: ; preds = %loop, %entry %iv = phi i64 [ 0, %entry ], [ %inc, %loop ] %r = phi i8 [ 0, %entry ], [ %add, %loop ] %arrayidx = getelementptr inbounds i32, i32* %src, i64 %iv %src_element = load i32, i32* %arrayidx, align 4 %array_const_idx = getelementptr inbounds [10 x i32], [10 x i32]* @known_constant, i64 0, i64 %iv %const_array_element = load i32, i32* %array_const_idx, align 4 %x = trunc i32 %src_element to i8 %y = trunc i32 %const_array_element to i8 %mul = mul nsw i8 %x, %y %add = add nsw i8 %mul, %r %inc = add nuw nsw i64 %iv, 1 %exitcond86.i = icmp eq i64 %inc, 10 br i1 %exitcond86.i, label %loop.end, label %loop loop.end: ; preds = %loop %r.lcssa = phi i8 [ %r, %loop ] ret i8 %r.lcssa } ; The same test as before, but with ZEXT instead of TRUNC. ; CHECK-LABEL: @const_load_zext ; CHECK-NOT: br i1 ; CHECK: ret i64 % define i64 @const_load_zext(i32* noalias nocapture readonly %src) { entry: br label %loop loop: ; preds = %loop, %entry %iv = phi i64 [ 0, %entry ], [ %inc, %loop ] %r = phi i64 [ 0, %entry ], [ %add, %loop ] %arrayidx = getelementptr inbounds i32, i32* %src, i64 %iv %src_element = load i32, i32* %arrayidx, align 4 %array_const_idx = getelementptr inbounds [10 x i32], [10 x i32]* @known_constant, i64 0, i64 %iv %const_array_element = load i32, i32* %array_const_idx, align 4 %x = zext i32 %src_element to i64 %y = zext i32 %const_array_element to i64 %mul = mul nsw i64 %x, %y %add = add nsw i64 %mul, %r %inc = add nuw nsw i64 %iv, 1 %exitcond86.i = icmp eq i64 %inc, 10 br i1 %exitcond86.i, label %loop.end, label %loop loop.end: ; preds = %loop %r.lcssa = phi i64 [ %r, %loop ] ret i64 %r.lcssa } ; The same test as the first one, but with SEXT instead of TRUNC. ; CHECK-LABEL: @const_load_sext ; CHECK-NOT: br i1 ; CHECK: ret i64 % define i64 @const_load_sext(i32* noalias nocapture readonly %src) { entry: br label %loop loop: ; preds = %loop, %entry %iv = phi i64 [ 0, %entry ], [ %inc, %loop ] %r = phi i64 [ 0, %entry ], [ %add, %loop ] %arrayidx = getelementptr inbounds i32, i32* %src, i64 %iv %src_element = load i32, i32* %arrayidx, align 4 %array_const_idx = getelementptr inbounds [10 x i32], [10 x i32]* @known_constant, i64 0, i64 %iv %const_array_element = load i32, i32* %array_const_idx, align 4 %x = sext i32 %src_element to i64 %y = sext i32 %const_array_element to i64 %mul = mul nsw i64 %x, %y %add = add nsw i64 %mul, %r %inc = add nuw nsw i64 %iv, 1 %exitcond86.i = icmp eq i64 %inc, 10 br i1 %exitcond86.i, label %loop.end, label %loop loop.end: ; preds = %loop %r.lcssa = phi i64 [ %r, %loop ] ret i64 %r.lcssa }