}
; TODO: We can break the backedge here.
-define i32 @test_switch(i32 %limit) {
-; CHECK-LABEL: @test_switch(
+define i32 @test_select(i32 %limit) {
+; CHECK-LABEL: @test_select(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[LOOP_GUARD:%.*]] = icmp sgt i32 [[LIMIT:%.*]], 0
; CHECK-NEXT: br i1 [[LOOP_GUARD]], label [[LOOP_PREHEADER:%.*]], label [[FAILURE:%.*]]
failure:
unreachable
}
+
+; TODO: We can break the backedge here.
+define i32 @test_select_const(i32 %x) {
+; CHECK-LABEL: @test_select_const(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: br label [[LOOP:%.*]]
+; CHECK: loop:
+; CHECK-NEXT: [[SUM:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[SUM_NEXT:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT: [[SUB:%.*]] = sub i32 4, [[SUM]]
+; CHECK-NEXT: [[IS_POSITIVE:%.*]] = icmp sgt i32 [[SUB]], 0
+; CHECK-NEXT: [[SEL:%.*]] = select i1 [[IS_POSITIVE]], i32 [[SUB]], i32 [[X:%.*]]
+; CHECK-NEXT: [[SEL_COND:%.*]] = icmp sgt i32 [[SEL]], 0
+; CHECK-NEXT: br i1 [[SEL_COND]], label [[BACKEDGE]], label [[IF_FALSE:%.*]]
+; CHECK: if.false:
+; CHECK-NEXT: br label [[BACKEDGE]]
+; CHECK: backedge:
+; CHECK-NEXT: [[MERGE_PHI:%.*]] = phi i32 [ 0, [[IF_FALSE]] ], [ [[SUB]], [[LOOP]] ]
+; CHECK-NEXT: [[SUM_NEXT]] = add i32 [[SUM]], [[MERGE_PHI]]
+; CHECK-NEXT: [[LOOP_COND:%.*]] = icmp ne i32 [[SUM_NEXT]], 4
+; CHECK-NEXT: br i1 [[LOOP_COND]], label [[LOOP]], label [[DONE:%.*]]
+; CHECK: done:
+; CHECK-NEXT: [[SUM_NEXT_LCSSA:%.*]] = phi i32 [ [[SUM_NEXT]], [[BACKEDGE]] ]
+; CHECK-NEXT: ret i32 [[SUM_NEXT_LCSSA]]
+;
+entry:
+ br label %loop
+
+loop: ; preds = %backedge, %entry
+ %sum = phi i32 [ 0, %entry ], [ %sum.next, %backedge ]
+ %sub = sub i32 4, %sum
+ %is.positive = icmp sgt i32 %sub, 0
+ %sel = select i1 %is.positive, i32 %sub, i32 %x
+ %sel.cond = icmp sgt i32 %sel, 0
+ br i1 %sel.cond, label %backedge, label %if.false
+
+if.false: ; preds = %loop
+ br label %backedge
+
+backedge: ; preds = %if.false, %loop
+ %merge.phi = phi i32 [ 0, %if.false ], [ %sub, %loop ]
+ %sum.next = add i32 %sum, %merge.phi
+ %loop.cond = icmp ne i32 %sum.next, 4
+ br i1 %loop.cond, label %loop, label %done
+
+done: ; preds = %backedge
+ %sum.next.lcssa = phi i32 [ %sum.next, %backedge ]
+ ret i32 %sum.next.lcssa
+}