; RUN: opt -S -basicaa -licm < %s | FileCheck %s target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" target triple = "x86_64-unknown-linux-gnu" ; This test represents the following function: ; void test1(int * __restrict__ a, int * __restrict__ b, int &c, int n) { ; for (int i = 0; i < n; ++i) ; if (a[i] > 0) ; a[i] = c*b[i]; ; } ; and we want to hoist the load of %c out of the loop. This can be done only ; because the dereferenceable attribute is on %c. ; CHECK-LABEL: @test1 ; CHECK: load i32, i32* %c, align 4 ; CHECK: for.body: define void @test1(i32* noalias nocapture %a, i32* noalias nocapture readonly %b, i32* nocapture readonly nonnull dereferenceable(4) %c, i32 %n) #0 { entry: %cmp11 = icmp sgt i32 %n, 0 br i1 %cmp11, label %for.body, label %for.end for.body: ; preds = %entry, %for.inc %indvars.iv = phi i64 [ %indvars.iv.next, %for.inc ], [ 0, %entry ] %arrayidx = getelementptr inbounds i32, i32* %a, i64 %indvars.iv %0 = load i32, i32* %arrayidx, align 4 %cmp1 = icmp sgt i32 %0, 0 br i1 %cmp1, label %if.then, label %for.inc if.then: ; preds = %for.body %1 = load i32, i32* %c, align 4 %arrayidx3 = getelementptr inbounds i32, i32* %b, i64 %indvars.iv %2 = load i32, i32* %arrayidx3, align 4 %mul = mul nsw i32 %2, %1 store i32 %mul, i32* %arrayidx, align 4 br label %for.inc for.inc: ; preds = %for.body, %if.then %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 %lftr.wideiv = trunc i64 %indvars.iv.next to i32 %exitcond = icmp eq i32 %lftr.wideiv, %n br i1 %exitcond, label %for.end, label %for.body for.end: ; preds = %for.inc, %entry ret void } ; This is the same as @test1, but without the dereferenceable attribute on %c. ; Without this attribute, we should not hoist the load of %c. ; CHECK-LABEL: @test2 ; CHECK: if.then: ; CHECK: load i32, i32* %c, align 4 define void @test2(i32* noalias nocapture %a, i32* noalias nocapture readonly %b, i32* nocapture readonly nonnull %c, i32 %n) #0 { entry: %cmp11 = icmp sgt i32 %n, 0 br i1 %cmp11, label %for.body, label %for.end for.body: ; preds = %entry, %for.inc %indvars.iv = phi i64 [ %indvars.iv.next, %for.inc ], [ 0, %entry ] %arrayidx = getelementptr inbounds i32, i32* %a, i64 %indvars.iv %0 = load i32, i32* %arrayidx, align 4 %cmp1 = icmp sgt i32 %0, 0 br i1 %cmp1, label %if.then, label %for.inc if.then: ; preds = %for.body %1 = load i32, i32* %c, align 4 %arrayidx3 = getelementptr inbounds i32, i32* %b, i64 %indvars.iv %2 = load i32, i32* %arrayidx3, align 4 %mul = mul nsw i32 %2, %1 store i32 %mul, i32* %arrayidx, align 4 br label %for.inc for.inc: ; preds = %for.body, %if.then %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 %lftr.wideiv = trunc i64 %indvars.iv.next to i32 %exitcond = icmp eq i32 %lftr.wideiv, %n br i1 %exitcond, label %for.end, label %for.body for.end: ; preds = %for.inc, %entry ret void } ; This test represents the following function: ; void test3(int * restrict a, int * restrict b, int c[static 3], int n) { ; for (int i = 0; i < n; ++i) ; if (a[i] > 0) ; a[i] = c[2]*b[i]; ; } ; and we want to hoist the load of c[2] out of the loop. This can be done only ; because the dereferenceable attribute is on %c. ; CHECK-LABEL: @test3 ; CHECK: load i32, i32* %c2, align 4 ; CHECK: for.body: define void @test3(i32* noalias nocapture %a, i32* noalias nocapture readonly %b, i32* nocapture readonly dereferenceable(12) %c, i32 %n) #0 { entry: %cmp11 = icmp sgt i32 %n, 0 br i1 %cmp11, label %for.body, label %for.end for.body: ; preds = %entry, %for.inc %indvars.iv = phi i64 [ %indvars.iv.next, %for.inc ], [ 0, %entry ] %arrayidx = getelementptr inbounds i32, i32* %a, i64 %indvars.iv %0 = load i32, i32* %arrayidx, align 4 %cmp1 = icmp sgt i32 %0, 0 br i1 %cmp1, label %if.then, label %for.inc if.then: ; preds = %for.body %c2 = getelementptr inbounds i32, i32* %c, i64 2 %1 = load i32, i32* %c2, align 4 %arrayidx3 = getelementptr inbounds i32, i32* %b, i64 %indvars.iv %2 = load i32, i32* %arrayidx3, align 4 %mul = mul nsw i32 %2, %1 store i32 %mul, i32* %arrayidx, align 4 br label %for.inc for.inc: ; preds = %for.body, %if.then %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 %lftr.wideiv = trunc i64 %indvars.iv.next to i32 %exitcond = icmp eq i32 %lftr.wideiv, %n br i1 %exitcond, label %for.end, label %for.body for.end: ; preds = %for.inc, %entry ret void } ; This is the same as @test3, but with a dereferenceable attribute on %c with a ; size too small to cover c[2] (and so we should not hoist it). ; CHECK-LABEL: @test4 ; CHECK: if.then: ; CHECK: load i32, i32* %c2, align 4 define void @test4(i32* noalias nocapture %a, i32* noalias nocapture readonly %b, i32* nocapture readonly dereferenceable(11) %c, i32 %n) #0 { entry: %cmp11 = icmp sgt i32 %n, 0 br i1 %cmp11, label %for.body, label %for.end for.body: ; preds = %entry, %for.inc %indvars.iv = phi i64 [ %indvars.iv.next, %for.inc ], [ 0, %entry ] %arrayidx = getelementptr inbounds i32, i32* %a, i64 %indvars.iv %0 = load i32, i32* %arrayidx, align 4 %cmp1 = icmp sgt i32 %0, 0 br i1 %cmp1, label %if.then, label %for.inc if.then: ; preds = %for.body %c2 = getelementptr inbounds i32, i32* %c, i64 2 %1 = load i32, i32* %c2, align 4 %arrayidx3 = getelementptr inbounds i32, i32* %b, i64 %indvars.iv %2 = load i32, i32* %arrayidx3, align 4 %mul = mul nsw i32 %2, %1 store i32 %mul, i32* %arrayidx, align 4 br label %for.inc for.inc: ; preds = %for.body, %if.then %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 %lftr.wideiv = trunc i64 %indvars.iv.next to i32 %exitcond = icmp eq i32 %lftr.wideiv, %n br i1 %exitcond, label %for.end, label %for.body for.end: ; preds = %for.inc, %entry ret void } attributes #0 = { nounwind uwtable }