llvm/test/Transforms/LoopInterchange/bail-out-one-loop.ll

; REQUIRES: asserts

; RUN: opt < %s -passes=loop-interchange -debug -disable-output 2>&1 | FileCheck %s

target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128-Fn32"

@N = dso_local global i32 0, align 4
@a = dso_local global ptr null, align 8
@b = dso_local global ptr null, align 8
@c = dso_local global ptr null, align 8

; Loop interchange should not run delinearization
; for one loop case and should bail out early.

; CHECK-NOT: Delinearizing
; CHECK-NOT: Strides:
; CHECK-NOT: Terms:
; CHECK: No Valid candidates for loop interchange.

define void @foo() {
entry:
  %retval = alloca i32, align 4
  %i = alloca i32, align 4
  store i32 0, ptr %retval, align 4
  store i32 0, ptr %i, align 4
  br label %for.cond

for.cond:                                         ; preds = %for.inc, %entry
  %0 = load i32, ptr %i, align 4
  %1 = load i32, ptr @N, align 4
  %cmp = icmp ult i32 %0, %1
  br i1 %cmp, label %for.body, label %for.cond.cleanup

for.cond.cleanup:                                 ; preds = %for.cond
  br label %for.end

for.body:                                         ; preds = %for.cond
  %2 = load ptr, ptr @b, align 8
  %3 = load i32, ptr %i, align 4
  %idxprom = zext i32 %3 to i64
  %arrayidx = getelementptr inbounds nuw i32, ptr %2, i64 %idxprom
  %4 = load i32, ptr %arrayidx, align 4
  %5 = load ptr, ptr @c, align 8
  %6 = load i32, ptr %i, align 4
  %idxprom1 = zext i32 %6 to i64
  %arrayidx2 = getelementptr inbounds nuw i32, ptr %5, i64 %idxprom1
  %7 = load i32, ptr %arrayidx2, align 4
  %add = add nsw i32 %4, %7
  %8 = load ptr, ptr @a, align 8
  %9 = load i32, ptr %i, align 4
  %idxprom3 = zext i32 %9 to i64
  %arrayidx4 = getelementptr inbounds nuw i32, ptr %8, i64 %idxprom3
  store i32 %add, ptr %arrayidx4, align 4
  br label %for.inc

for.inc:                                          ; preds = %for.body
  %10 = load i32, ptr %i, align 4
  %inc = add i32 %10, 1
  store i32 %inc, ptr %i, align 4
  br label %for.cond

for.end:                                          ; preds = %for.cond.cleanup
  ret void
}