Clean up spill weight computation. Also some changes to give loop induction
variable increment / decrement slighter high priority.
This has major impact on some micro-benchmarks. On MultiSource/Applications
and spec tests, it's a minor win. It also reduce 256.bzip instruction count
by 8%, 55 on 164.gzip on i386 / Darwin.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82485 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/CodeGen/X86/2009-09-21-NoSpillLoopCount.ll b/test/CodeGen/X86/2009-09-21-NoSpillLoopCount.ll
new file mode 100644
index 0000000..80b8835
--- /dev/null
+++ b/test/CodeGen/X86/2009-09-21-NoSpillLoopCount.ll
@@ -0,0 +1,36 @@
+; RUN: llc < %s -mtriple=i386-apple-darwin10.0 -relocation-model=pic | FileCheck %s
+
+define void @dot(i16* nocapture %A, i32 %As, i16* nocapture %B, i32 %Bs, i16* nocapture %C, i32 %N) nounwind ssp {
+; CHECK: dot:
+; CHECK: decl %
+; CHECK-NEXT: jne
+entry:
+ %0 = icmp sgt i32 %N, 0 ; <i1> [#uses=1]
+ br i1 %0, label %bb, label %bb2
+
+bb: ; preds = %bb, %entry
+ %i.03 = phi i32 [ 0, %entry ], [ %indvar.next, %bb ] ; <i32> [#uses=3]
+ %sum.04 = phi i32 [ 0, %entry ], [ %10, %bb ] ; <i32> [#uses=1]
+ %1 = mul i32 %i.03, %As ; <i32> [#uses=1]
+ %2 = getelementptr i16* %A, i32 %1 ; <i16*> [#uses=1]
+ %3 = load i16* %2, align 2 ; <i16> [#uses=1]
+ %4 = sext i16 %3 to i32 ; <i32> [#uses=1]
+ %5 = mul i32 %i.03, %Bs ; <i32> [#uses=1]
+ %6 = getelementptr i16* %B, i32 %5 ; <i16*> [#uses=1]
+ %7 = load i16* %6, align 2 ; <i16> [#uses=1]
+ %8 = sext i16 %7 to i32 ; <i32> [#uses=1]
+ %9 = mul i32 %8, %4 ; <i32> [#uses=1]
+ %10 = add i32 %9, %sum.04 ; <i32> [#uses=2]
+ %indvar.next = add i32 %i.03, 1 ; <i32> [#uses=2]
+ %exitcond = icmp eq i32 %indvar.next, %N ; <i1> [#uses=1]
+ br i1 %exitcond, label %bb1.bb2_crit_edge, label %bb
+
+bb1.bb2_crit_edge: ; preds = %bb
+ %phitmp = trunc i32 %10 to i16 ; <i16> [#uses=1]
+ br label %bb2
+
+bb2: ; preds = %entry, %bb1.bb2_crit_edge
+ %sum.0.lcssa = phi i16 [ %phitmp, %bb1.bb2_crit_edge ], [ 0, %entry ] ; <i16> [#uses=1]
+ store i16 %sum.0.lcssa, i16* %C, align 2
+ ret void
+}