Add an unfolded offset field to LSR's Formula record. This is used to

model constants which can be added to base registers via add-immediate
instructions which don't require an additional register to materialize
the immediate.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130743 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 80 insertions, 0 deletions

diff --git a/test/CodeGen/ARM/lsr-unfolded-offset.ll b/test/CodeGen/ARM/lsr-unfolded-offset.ll
new file mode 100644
index 0000000..a3342c6
--- /dev/null
+++ b/test/CodeGen/ARM/lsr-unfolded-offset.ll
@@ -0,0 +1,80 @@
+; RUN: llc < %s | FileCheck %s
+
+; LSR shouldn't introduce more induction variables than needed, increasing
+; register pressure and therefore spilling. There is more room for improvement
+; here.
+
+; CHECK: sub sp, #32
+
+; CHECK:      ldr r{{.*}}, [sp, #4]
+; CHECK-NEXT: ldr r{{.*}}, [sp, #16]
+; CHECK-NEXT: ldr r{{.*}}, [sp, #12]
+; CHECK-NEXT: adds
+
+target datalayout = "e-p:32:32:32-i1:8:32-i8:8:32-i16:16:32-i32:32:32-i64:32:32-f32:32:32-f64:32:32-v64:32:64-v128:32:128-a0:0:32-n32"
+target triple = "thumbv7-apple-macosx10.7.0"
+
+%struct.partition_entry = type { i32, i32, i64, i64 }
+
+define i32 @partition_overlap_check(%struct.partition_entry* nocapture %part, i32 %num_entries) nounwind readonly optsize ssp {
+entry:
+  %cmp79 = icmp sgt i32 %num_entries, 0
+  br i1 %cmp79, label %outer.loop, label %for.end72
+
+outer.loop:                                 ; preds = %for.inc69, %entry
+  %overlap.081 = phi i32 [ %overlap.4, %for.inc69 ], [ 0, %entry ]
+  %0 = phi i32 [ %inc71, %for.inc69 ], [ 0, %entry ]
+  %offset = getelementptr %struct.partition_entry* %part, i32 %0, i32 2
+  %len = getelementptr %struct.partition_entry* %part, i32 %0, i32 3
+  %tmp5 = load i64* %offset, align 4, !tbaa !0
+  %tmp15 = load i64* %len, align 4, !tbaa !0
+  %add = add nsw i64 %tmp15, %tmp5
+  br label %inner.loop
+
+inner.loop:                                       ; preds = %for.inc, %outer.loop
+  %overlap.178 = phi i32 [ %overlap.081, %outer.loop ], [ %overlap.4, %for.inc ]
+  %1 = phi i32 [ 0, %outer.loop ], [ %inc, %for.inc ]
+  %cmp23 = icmp eq i32 %0, %1
+  br i1 %cmp23, label %for.inc, label %if.end
+
+if.end:                                           ; preds = %inner.loop
+  %len39 = getelementptr %struct.partition_entry* %part, i32 %1, i32 3
+  %offset28 = getelementptr %struct.partition_entry* %part, i32 %1, i32 2
+  %tmp29 = load i64* %offset28, align 4, !tbaa !0
+  %tmp40 = load i64* %len39, align 4, !tbaa !0
+  %add41 = add nsw i64 %tmp40, %tmp29
+  %cmp44 = icmp sge i64 %tmp29, %tmp5
+  %cmp47 = icmp slt i64 %tmp29, %add
+  %or.cond = and i1 %cmp44, %cmp47
+  %overlap.2 = select i1 %or.cond, i32 1, i32 %overlap.178
+  %cmp52 = icmp sle i64 %add41, %add
+  %cmp56 = icmp sgt i64 %add41, %tmp5
+  %or.cond74 = and i1 %cmp52, %cmp56
+  %overlap.3 = select i1 %or.cond74, i32 1, i32 %overlap.2
+  %cmp61 = icmp sgt i64 %tmp29, %tmp5
+  %cmp65 = icmp slt i64 %add41, %add
+  %or.cond75 = or i1 %cmp61, %cmp65
+  br i1 %or.cond75, label %for.inc, label %if.then66
+
+if.then66:                                        ; preds = %if.end
+  br label %for.inc
+
+for.inc:                                          ; preds = %if.end, %if.then66, %inner.loop
+  %overlap.4 = phi i32 [ %overlap.178, %inner.loop ], [ 1, %if.then66 ], [ %overlap.3, %if.end ]
+  %inc = add nsw i32 %1, 1
+  %exitcond = icmp eq i32 %inc, %num_entries
+  br i1 %exitcond, label %for.inc69, label %inner.loop
+
+for.inc69:                                        ; preds = %for.inc
+  %inc71 = add nsw i32 %0, 1
+  %exitcond83 = icmp eq i32 %inc71, %num_entries
+  br i1 %exitcond83, label %for.end72, label %outer.loop
+
+for.end72:                                        ; preds = %for.inc69, %entry
+  %overlap.0.lcssa = phi i32 [ 0, %entry ], [ %overlap.4, %for.inc69 ]
+  ret i32 %overlap.0.lcssa
+}
+
+!0 = metadata !{metadata !"long long", metadata !1}
+!1 = metadata !{metadata !"omnipotent char", metadata !2}
+!2 = metadata !{metadata !"Simple C/C++ TBAA", null}