1; RUN: llc -mtriple=arm-eabi %s -o - | FileCheck %s 2 3; This loop is rewritten with an indvar which counts down, which 4; frees up a register from holding the trip count. 5 6define void @test(i32* %P, i32 %A, i32 %i) nounwind { 7entry: 8; CHECK: str r1, [{{r.*}}, {{r.*}}, lsl #2] 9 icmp eq i32 %i, 0 ; <i1>:0 [#uses=1] 10 br i1 %0, label %return, label %bb 11 12bb: ; preds = %bb, %entry 13 %indvar = phi i32 [ 0, %entry ], [ %indvar.next, %bb ] ; <i32> [#uses=2] 14 %i_addr.09.0 = sub i32 %i, %indvar ; <i32> [#uses=1] 15 %tmp2 = getelementptr i32, i32* %P, i32 %i_addr.09.0 ; <i32*> [#uses=1] 16 store i32 %A, i32* %tmp2 17 %indvar.next = add i32 %indvar, 1 ; <i32> [#uses=2] 18 icmp eq i32 %indvar.next, %i ; <i1>:1 [#uses=1] 19 br i1 %1, label %return, label %bb 20 21return: ; preds = %bb, %entry 22 ret void 23} 24 25; This loop has a non-address use of the count-up indvar, so 26; it'll remain. Now the original store uses a negative-stride address. 27 28define void @test_with_forced_iv(i32* %P, i32 %A, i32 %i) nounwind { 29entry: 30; CHECK: str r1, [{{r.*}}, -{{r.*}}, lsl #2] 31 icmp eq i32 %i, 0 ; <i1>:0 [#uses=1] 32 br i1 %0, label %return, label %bb 33 34bb: ; preds = %bb, %entry 35 %indvar = phi i32 [ 0, %entry ], [ %indvar.next, %bb ] ; <i32> [#uses=2] 36 %i_addr.09.0 = sub i32 %i, %indvar ; <i32> [#uses=1] 37 %tmp2 = getelementptr i32, i32* %P, i32 %i_addr.09.0 ; <i32*> [#uses=1] 38 store i32 %A, i32* %tmp2 39 store i32 %indvar, i32* null 40 %indvar.next = add i32 %indvar, 1 ; <i32> [#uses=2] 41 icmp eq i32 %indvar.next, %i ; <i1>:1 [#uses=1] 42 br i1 %1, label %return, label %bb 43 44return: ; preds = %bb, %entry 45 ret void 46} 47 48