1 files changed, 96 insertions, 0 deletions
diff --git a/test/Transforms/LoopStrengthReduce/X86/ivchain-stress-X86.ll b/test/Transforms/LoopStrengthReduce/X86/ivchain-stress-X86.ll
new file mode 100644
index 0000000..d8e0aa9
--- /dev/null
+++ b/test/Transforms/LoopStrengthReduce/X86/ivchain-stress-X86.ll
@@ -0,0 +1,96 @@
+; REQUIRES: asserts
+; RUN: llc < %s -O3 -march=x86-64 -mcpu=core2 -stress-ivchain | FileCheck %s -check-prefix=X64
+; RUN: llc < %s -O3 -march=x86 -mcpu=core2 -stress-ivchain | FileCheck %s -check-prefix=X32
+
+; @sharedidx is an unrolled variant of this loop:
+;  for (unsigned long i = 0; i < len; i += s) {
+;    c[i] = a[i] + b[i];
+;  }
+; where 's' cannot be folded into the addressing mode.
+;
+; This is not quite profitable to chain. But with -stress-ivchain, we
+; can form three address chains in place of the shared induction
+; variable.
+
+; X64: sharedidx:
+; X64: %for.body.preheader
+; X64-NOT: leal ({{.*}},4)
+; X64: %for.body.1
+
+; X32: sharedidx:
+; X32: %for.body.2
+; X32: add
+; X32: add
+; X32: add
+; X32: add
+; X32: add
+; X32: %for.body.3
+define void @sharedidx(i8* nocapture %a, i8* nocapture %b, i8* nocapture %c, i32 %s, i32 %len) nounwind ssp {
+entry:
+  %cmp8 = icmp eq i32 %len, 0
+  br i1 %cmp8, label %for.end, label %for.body
+
+for.body:                                         ; preds = %entry, %for.body.3
+  %i.09 = phi i32 [ %add5.3, %for.body.3 ], [ 0, %entry ]
+  %arrayidx = getelementptr inbounds i8* %a, i32 %i.09
+  %0 = load i8* %arrayidx, align 1
+  %conv6 = zext i8 %0 to i32
+  %arrayidx1 = getelementptr inbounds i8* %b, i32 %i.09
+  %1 = load i8* %arrayidx1, align 1
+  %conv27 = zext i8 %1 to i32
+  %add = add nsw i32 %conv27, %conv6
+  %conv3 = trunc i32 %add to i8
+  %arrayidx4 = getelementptr inbounds i8* %c, i32 %i.09
+  store i8 %conv3, i8* %arrayidx4, align 1
+  %add5 = add i32 %i.09, %s
+  %cmp = icmp ult i32 %add5, %len
+  br i1 %cmp, label %for.body.1, label %for.end
+
+for.end:                                          ; preds = %for.body, %for.body.1, %for.body.2, %for.body.3, %entry
+  ret void
+
+for.body.1:                                       ; preds = %for.body
+  %arrayidx.1 = getelementptr inbounds i8* %a, i32 %add5
+  %2 = load i8* %arrayidx.1, align 1
+  %conv6.1 = zext i8 %2 to i32
+  %arrayidx1.1 = getelementptr inbounds i8* %b, i32 %add5
+  %3 = load i8* %arrayidx1.1, align 1
+  %conv27.1 = zext i8 %3 to i32
+  %add.1 = add nsw i32 %conv27.1, %conv6.1
+  %conv3.1 = trunc i32 %add.1 to i8
+  %arrayidx4.1 = getelementptr inbounds i8* %c, i32 %add5
+  store i8 %conv3.1, i8* %arrayidx4.1, align 1
+  %add5.1 = add i32 %add5, %s
+  %cmp.1 = icmp ult i32 %add5.1, %len
+  br i1 %cmp.1, label %for.body.2, label %for.end
+
+for.body.2:                                       ; preds = %for.body.1
+  %arrayidx.2 = getelementptr inbounds i8* %a, i32 %add5.1
+  %4 = load i8* %arrayidx.2, align 1
+  %conv6.2 = zext i8 %4 to i32
+  %arrayidx1.2 = getelementptr inbounds i8* %b, i32 %add5.1
+  %5 = load i8* %arrayidx1.2, align 1
+  %conv27.2 = zext i8 %5 to i32
+  %add.2 = add nsw i32 %conv27.2, %conv6.2
+  %conv3.2 = trunc i32 %add.2 to i8
+  %arrayidx4.2 = getelementptr inbounds i8* %c, i32 %add5.1
+  store i8 %conv3.2, i8* %arrayidx4.2, align 1
+  %add5.2 = add i32 %add5.1, %s
+  %cmp.2 = icmp ult i32 %add5.2, %len
+  br i1 %cmp.2, label %for.body.3, label %for.end
+
+for.body.3:                                       ; preds = %for.body.2
+  %arrayidx.3 = getelementptr inbounds i8* %a, i32 %add5.2
+  %6 = load i8* %arrayidx.3, align 1
+  %conv6.3 = zext i8 %6 to i32
+  %arrayidx1.3 = getelementptr inbounds i8* %b, i32 %add5.2
+  %7 = load i8* %arrayidx1.3, align 1
+  %conv27.3 = zext i8 %7 to i32
+  %add.3 = add nsw i32 %conv27.3, %conv6.3
+  %conv3.3 = trunc i32 %add.3 to i8
+  %arrayidx4.3 = getelementptr inbounds i8* %c, i32 %add5.2
+  store i8 %conv3.3, i8* %arrayidx4.3, align 1
+  %add5.3 = add i32 %add5.2, %s
+  %cmp.3 = icmp ult i32 %add5.3, %len
+  br i1 %cmp.3, label %for.body, label %for.end
+}