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; RUN: opt < %s -S -passes='loop(loop-flatten),verify' -verify-loop-info -verify-dom-info -verify-scev | FileCheck %s
target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
; We should be able to flatten the loops and turn the two geps into one.
; CHECK-LABEL: test1
define void @test1(i32 %N, ptr %A) {
entry:
%cmp3 = icmp ult i32 0, %N
br i1 %cmp3, label %for.outer.preheader, label %for.end
; CHECK-LABEL: for.outer.preheader:
; CHECK: %flatten.tripcount = mul i32 %N, %N
for.outer.preheader:
br label %for.inner.preheader
; CHECK-LABEL: for.inner.preheader:
; CHECK: %flatten.arrayidx = getelementptr inbounds i32, ptr %A, i32 %i
for.inner.preheader:
%i = phi i32 [ 0, %for.outer.preheader ], [ %inc2, %for.outer ]
br label %for.inner
; CHECK-LABEL: for.inner:
; CHECK: store i32 0, ptr %flatten.arrayidx, align 4
; CHECK: br label %for.outer
for.inner:
%j = phi i32 [ 0, %for.inner.preheader ], [ %inc1, %for.inner ]
%mul = mul i32 %i, %N
%gep = getelementptr inbounds i32, ptr %A, i32 %mul
%arrayidx = getelementptr inbounds i32, ptr %gep, i32 %j
store i32 0, ptr %arrayidx, align 4
%inc1 = add nuw i32 %j, 1
%cmp2 = icmp ult i32 %inc1, %N
br i1 %cmp2, label %for.inner, label %for.outer
; CHECK-LABEL: for.outer:
; CHECK: %cmp1 = icmp ult i32 %inc2, %flatten.tripcount
for.outer:
%inc2 = add i32 %i, 1
%cmp1 = icmp ult i32 %inc2, %N
br i1 %cmp1, label %for.inner.preheader, label %for.end.loopexit
for.end.loopexit:
br label %for.end
for.end:
ret void
}
; We can flatten, but the flattened gep has to be inserted after the load it
; depends on.
; CHECK-LABEL: test2
define void @test2(i32 %N, ptr %A) {
entry:
%cmp3 = icmp ult i32 0, %N
br i1 %cmp3, label %for.outer.preheader, label %for.end
; CHECK-LABEL: for.outer.preheader:
; CHECK: %flatten.tripcount = mul i32 %N, %N
for.outer.preheader:
br label %for.inner.preheader
; CHECK-LABEL: for.inner.preheader:
; CHECK-NOT: getelementptr inbounds i32, ptr %ptr, i32 %i
for.inner.preheader:
%i = phi i32 [ 0, %for.outer.preheader ], [ %inc2, %for.outer ]
br label %for.inner
; CHECK-LABEL: for.inner:
; CHECK: %flatten.arrayidx = getelementptr inbounds i32, ptr %ptr, i32 %i
; CHECK: store i32 0, ptr %flatten.arrayidx, align 4
; CHECK: br label %for.outer
for.inner:
%j = phi i32 [ 0, %for.inner.preheader ], [ %inc1, %for.inner ]
%ptr = load volatile ptr, ptr %A, align 4
%mul = mul i32 %i, %N
%gep = getelementptr inbounds i32, ptr %ptr, i32 %mul
%arrayidx = getelementptr inbounds i32, ptr %gep, i32 %j
store i32 0, ptr %arrayidx, align 4
%inc1 = add nuw i32 %j, 1
%cmp2 = icmp ult i32 %inc1, %N
br i1 %cmp2, label %for.inner, label %for.outer
; CHECK-LABEL: for.outer:
; CHECK: %cmp1 = icmp ult i32 %inc2, %flatten.tripcount
for.outer:
%inc2 = add i32 %i, 1
%cmp1 = icmp ult i32 %inc2, %N
br i1 %cmp1, label %for.inner.preheader, label %for.end.loopexit
for.end.loopexit:
br label %for.end
for.end:
ret void
}
; We can't flatten if the gep offset is smaller than the pointer size.
; CHECK-LABEL: test3
define void @test3(i16 %N, ptr %A) {
entry:
%cmp3 = icmp ult i16 0, %N
br i1 %cmp3, label %for.outer.preheader, label %for.end
for.outer.preheader:
br label %for.inner.preheader
; CHECK-LABEL: for.inner.preheader:
; CHECK-NOT: getelementptr i32, ptr %A, i16 %i
for.inner.preheader:
%i = phi i16 [ 0, %for.outer.preheader ], [ %inc2, %for.outer ]
br label %for.inner
; CHECK-LABEL: for.inner:
; CHECK-NOT: getelementptr i32, ptr %A, i16 %i
; CHECK: br i1 %cmp2, label %for.inner, label %for.outer
for.inner:
%j = phi i16 [ 0, %for.inner.preheader ], [ %inc1, %for.inner ]
%mul = mul i16 %i, %N
%gep = getelementptr inbounds i32, ptr %A, i16 %mul
%arrayidx = getelementptr inbounds i32, ptr %gep, i16 %j
store i32 0, ptr %arrayidx, align 4
%inc1 = add nuw i16 %j, 1
%cmp2 = icmp ult i16 %inc1, %N
br i1 %cmp2, label %for.inner, label %for.outer
for.outer:
%inc2 = add i16 %i, 1
%cmp1 = icmp ult i16 %inc2, %N
br i1 %cmp1, label %for.inner.preheader, label %for.end.loopexit
for.end.loopexit:
br label %for.end
for.end:
ret void
}
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