[InstCombine] Precommit test case for D66216

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368978 91177308-0d34-0410-b5e6-96231b3b80d8

Author: fhahn

test/Transforms/InstCombine/phi-known-bits-operand-order.ll

@@ -0,0 +1,99 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -instcombine -S < %s | FileCheck %s
+
+; Check that we can turn the icmp sle into icmp ult, regardless of the
+; order of the incoming values of the PHI node.
+
+declare i1 @cond()
+
+define void @phi_recurrence_start_first() {
+; CHECK-LABEL: @phi_recurrence_start_first(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[WHILE_COND:%.*]]
+; CHECK:       while.cond:
+; CHECK-NEXT:    [[CELL_0:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[START:%.*]], [[FOR_COND26:%.*]] ]
+; CHECK-NEXT:    [[COND_V:%.*]] = call i1 @cond()
+; CHECK-NEXT:    br i1 [[COND_V]], label [[IF_THEN:%.*]], label [[WHILE_END:%.*]]
+; CHECK:       if.then:
+; CHECK-NEXT:    [[START]] = add nuw nsw i32 [[CELL_0]], 1
+; CHECK-NEXT:    br i1 [[COND_V]], label [[FOR_COND11:%.*]], label [[FOR_COND26]]
+; CHECK:       for.cond11:
+; CHECK-NEXT:    [[I_1:%.*]] = phi i32 [ [[START]], [[IF_THEN]] ], [ [[STEP:%.*]], [[FOR_COND11]] ]
+; CHECK-NEXT:    [[CMP13:%.*]] = icmp slt i32 [[I_1]], 100
+; CHECK-NEXT:    [[STEP]] = add nsw i32 [[I_1]], 1
+; CHECK-NEXT:    br i1 [[CMP13]], label [[FOR_COND11]], label [[WHILE_END]]
+; CHECK:       for.cond26:
+; CHECK-NEXT:    br label [[WHILE_COND]]
+; CHECK:       while.end:
+; CHECK-NEXT:    ret void
+;
+entry:
+  br label %while.cond
+
+while.cond:                                       ; preds = %entry, %for.cond26
+  %cell.0 = phi i32 [ 0, %entry ], [ %start, %for.cond26 ]
+  %cond.v = call i1 @cond()
+  br i1 %cond.v, label %if.then, label %while.end
+
+if.then:                                          ; preds = %while.cond
+  %start = add nsw i32 %cell.0, 1
+  br i1 %cond.v, label %for.cond11, label %for.cond26
+
+for.cond11:                                       ; preds = %for.cond11, %if.then
+  %i.1 = phi i32 [ %start, %if.then ], [ %step, %for.cond11 ]
+  %cmp13 = icmp sle i32 %i.1, 99
+  %step = add nsw i32 %i.1, 1
+  br i1 %cmp13, label %for.cond11, label %while.end
+
+for.cond26:                                       ; preds = %if.then
+  br label %while.cond
+
+while.end:                                        ; preds = %while.cond, %for.cond11
+  ret void
+}
+
+define void @phi_recurrence_step_first() {
+; CHECK-LABEL: @phi_recurrence_step_first(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[WHILE_COND:%.*]]
+; CHECK:       while.cond:
+; CHECK-NEXT:    [[CELL_0:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[START:%.*]], [[FOR_COND26:%.*]] ]
+; CHECK-NEXT:    [[COND_V:%.*]] = call i1 @cond()
+; CHECK-NEXT:    br i1 [[COND_V]], label [[IF_THEN:%.*]], label [[WHILE_END:%.*]]
+; CHECK:       if.then:
+; CHECK-NEXT:    [[START]] = add nuw nsw i32 [[CELL_0]], 1
+; CHECK-NEXT:    br i1 [[COND_V]], label [[FOR_COND11:%.*]], label [[FOR_COND26]]
+; CHECK:       for.cond11:
+; CHECK-NEXT:    [[I_1:%.*]] = phi i32 [ [[STEP:%.*]], [[FOR_COND11]] ], [ [[START]], [[IF_THEN]] ]
+; CHECK-NEXT:    [[CMP13:%.*]] = icmp ult i32 [[I_1]], 100
+; CHECK-NEXT:    [[STEP]] = add nuw nsw i32 [[I_1]], 1
+; CHECK-NEXT:    br i1 [[CMP13]], label [[FOR_COND11]], label [[WHILE_END]]
+; CHECK:       for.cond26:
+; CHECK-NEXT:    br label [[WHILE_COND]]
+; CHECK:       while.end:
+; CHECK-NEXT:    ret void
+;
+entry:
+  br label %while.cond
+
+while.cond:                                       ; preds = %entry, %for.cond26
+  %cell.0 = phi i32 [ 0, %entry ], [ %start, %for.cond26 ]
+  %cond.v = call i1 @cond()
+  br i1 %cond.v, label %if.then, label %while.end
+
+if.then:                                          ; preds = %while.cond
+  %start = add nsw i32 %cell.0, 1
+  br i1 %cond.v, label %for.cond11, label %for.cond26
+
+for.cond11:                                       ; preds = %for.cond11, %if.then
+  %i.1 = phi i32 [ %step, %for.cond11 ], [ %start, %if.then]
+  %cmp13 = icmp sle i32 %i.1, 99
+  %step = add nsw i32 %i.1, 1
+  br i1 %cmp13, label %for.cond11, label %while.end
+
+for.cond26:                                       ; preds = %if.then
+  br label %while.cond
+
+while.end:                                        ; preds = %while.cond, %for.cond11
+  ret void
+}