add test for this:

(1) Allow loop invariant expressions to come before the induction variable (instead of just
constants):

   int x;
   for (i)
    ...a[x][i]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20499 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/test/Transforms/LoopStrengthReduce/invariant_value_first.ll b/test/Transforms/LoopStrengthReduce/invariant_value_first.ll
new file mode 100644 (file)
index 0000000..8f16210
--- /dev/null
+++ b/test/Transforms/LoopStrengthReduce/invariant_value_first.ll
@@ -0,0 +1,21 @@
+; Check that the index of 'P[outer]' is pulled out of the loop.
+; RUN: llvm-as < %s | opt -loop-reduce | llvm-dis | not grep 'getelementptr.*%outer.*%INDVAR'
+
+declare bool %pred()
+declare int %foo()
+
+void %test([10000 x int]* %P) {
+       %outer = call int %foo()
+       br label %Loop
+Loop:
+       %INDVAR = phi int [0, %0], [%INDVAR2, %Loop]
+
+       %STRRED = getelementptr [10000 x int]* %P, int %outer, int %INDVAR
+       store int 0, int* %STRRED
+
+       %INDVAR2 = add int %INDVAR, 1
+       %cond = call bool %pred()
+       br bool %cond, label %Loop, label %Out
+Out:
+       ret void
+}