Unit test for LSR kind=Special fix: r158536.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158570 91177308-0d34-0410-b5e6-96231b3b80d8

test/Transforms/LoopStrengthReduce/ARM/2012-06-15-lsr-noaddrmode.ll

@@ -0,0 +1,102 @@
+; RUN: llc < %s -O3 -march=thumb -mcpu=cortex-a8 | FileCheck %s
+;
+; LSR should only check for valid address modes when the IV user is a
+; memory address.
+; svn r158536, rdar://11635990
+;
+; Note that we still don't produce the best code here because we fail
+; to coalesce the IV. See <rdar://problem/11680670> [coalescer] IVs
+; need to be scheduled to expose coalescing.
+
+; LSR before the fix:
+;The chosen solution requires 4 regs, with addrec cost 1, plus 3 base adds, plus 2 setup cost:
+;  LSR Use: Kind=Special, Offsets={0}, all-fixups-outside-loop, widest fixup type: i32
+;    reg(%v3) + reg({0,+,-1}<%while.cond.i.i>) + imm(1)
+;  LSR Use: Kind=ICmpZero, Offsets={0}, widest fixup type: i32
+;    reg(%v3) + reg({0,+,-1}<%while.cond.i.i>)
+;  LSR Use: Kind=Address of i32, Offsets={0}, widest fixup type: i32*
+;    reg((-4 + (4 * %v3) + %v1)) + 4*reg({0,+,-1}<%while.cond.i.i>)
+;  LSR Use: Kind=Address of i32, Offsets={0}, widest fixup type: i32*
+;    reg((-4 + (4 * %v3) + %v4)) + 4*reg({0,+,-1}<%while.cond.i.i>)
+;  LSR Use: Kind=Special, Offsets={0}, all-fixups-outside-loop, widest fixup type: i32
+;    reg(%v3)
+;
+; LSR after the fix:
+;The chosen solution requires 4 regs, with addrec cost 1, plus 1 base add, plus 2 setup cost:
+;  LSR Use: Kind=Special, Offsets={0}, all-fixups-outside-loop, widest fixup type: i32
+;    reg({%v3,+,-1}<nsw><%while.cond.i.i>) + imm(1)
+;  LSR Use: Kind=ICmpZero, Offsets={0}, widest fixup type: i32
+;    reg({%v3,+,-1}<nsw><%while.cond.i.i>)
+;  LSR Use: Kind=Address of i32, Offsets={0}, widest fixup type: i32*
+;    reg((-4 + %v1)) + 4*reg({%v3,+,-1}<nsw><%while.cond.i.i>)
+;  LSR Use: Kind=Address of i32, Offsets={0}, widest fixup type: i32*
+;    reg((-4 + %v4)) + 4*reg({%v3,+,-1}<nsw><%while.cond.i.i>)
+;  LSR Use: Kind=Special, Offsets={0}, all-fixups-outside-loop, widest fixup type: i32
+;    reg(%v3)
+
+
+%s = type { i32* }
+
+@ncol = external global i32, align 4
+
+declare i32* @getptr() nounwind
+declare %s* @getstruct() nounwind
+
+; CHECK: @main
+; Check that the loop preheader contains no address computation.
+; CHECK: %entry
+; CHECK-NOT: add{{.*}}lsl
+; CHECK: ldr{{.*}}lsl #2
+; CHECK: ldr{{.*}}lsl #2
+define i32 @main() nounwind ssp {
+entry:
+  %v0 = load i32* @ncol, align 4, !tbaa !0
+  %v1 = tail call i32* @getptr() nounwind
+  %cmp10.i = icmp eq i32 %v0, 0
+  br label %while.cond.outer
+
+while.cond.outer:
+  %call18 = tail call %s* @getstruct() nounwind
+  br label %while.cond
+
+while.cond:
+  %cmp20 = icmp eq i32* %v1, null
+  br label %while.body
+
+while.body:
+  %v3 = load i32* @ncol, align 4, !tbaa !0
+  br label %while.cond.i
+
+while.cond.i:
+  %state.i = getelementptr inbounds %s* %call18, i32 0, i32 0
+  %v4 = load i32** %state.i, align 4, !tbaa !3
+  br label %while.cond.i.i
+
+while.cond.i.i:
+  %counter.0.i.i = phi i32 [ %v3, %while.cond.i ], [ %dec.i.i, %land.rhs.i.i ]
+  %dec.i.i = add nsw i32 %counter.0.i.i, -1
+  %tobool.i.i = icmp eq i32 %counter.0.i.i, 0
+  br i1 %tobool.i.i, label %where.exit, label %land.rhs.i.i
+
+land.rhs.i.i:
+  %arrayidx.i.i = getelementptr inbounds i32* %v4, i32 %dec.i.i
+  %v5 = load i32* %arrayidx.i.i, align 4, !tbaa !0
+  %arrayidx1.i.i = getelementptr inbounds i32* %v1, i32 %dec.i.i
+  %v6 = load i32* %arrayidx1.i.i, align 4, !tbaa !0
+  %cmp.i.i = icmp eq i32 %v5, %v6
+  br i1 %cmp.i.i, label %while.cond.i.i, label %equal_data.exit.i
+
+equal_data.exit.i:
+  ret i32 %counter.0.i.i
+
+where.exit:
+  br label %while.end.i
+
+while.end.i:
+  ret i32 %v3
+}
+
+!0 = metadata !{metadata !"int", metadata !1}
+!1 = metadata !{metadata !"omnipotent char", metadata !2}
+!2 = metadata !{metadata !"Simple C/C++ TBAA"}
+!3 = metadata !{metadata !"any pointer", metadata !1}