1 ; RUN: llc < %s -mtriple=thumbv7-apple-ios -mcpu=cortex-a9 -jump-table-density=40 | FileCheck %s 2 ; Test that ldmia_ret preserves implicit operands for return values. 3 ; 4 ; This CFG is reduced from a benchmark miscompile. With current 5 ; if-conversion heuristics, one of the return paths is if-converted 6 ; into sw.bb18 resulting in an ldmia_ret in the middle of the 7 ; block. The postra scheduler needs to know that the return implicitly 8 ; uses the return register, otherwise its antidep breaker scavenges 9 ; the register in order to hoist the constant load required to test 10 ; the switch. 11 12 declare i32 @getint() 13 declare i1 @getbool() 14 declare void @foo(i32) 15 declare i32 @bar(i32) 16 17 define i32 @test(i32 %in1, i32 %in2) nounwind { 18 entry: 19 %call = tail call zeroext i1 @getbool() nounwind 20 br i1 %call, label %sw.bb18, label %sw.bb2 21 22 sw.bb2: ; preds = %entry 23 %cmp = tail call zeroext i1 @getbool() nounwind 24 br i1 %cmp, label %sw.epilog58, label %land.lhs.true 25 26 land.lhs.true: ; preds = %sw.bb2 27 %cmp13 = tail call zeroext i1 @getbool() nounwind 28 br i1 %cmp13, label %if.then, label %sw.epilog58 29 30 if.then: ; preds = %land.lhs.true 31 tail call void @foo(i32 %in1) nounwind 32 br label %sw.epilog58 33 34 ; load the return value 35 ; CHECK: movs [[RRET:r.]], #2 36 ; hoist the switch constant without clobbering RRET 37 ; CHECK: movw 38 ; CHECK-NOT: [[RRET]] 39 ; CHECK: , #63707 40 ; CHECK-NOT: [[RRET]] 41 ; CHECK: tst 42 ; If-convert the return 43 ; CHECK: it ne 44 ; Fold the CSR+return into a pop 45 ; CHECK: pop {r4, r5, r7, pc} 46 sw.bb18: 47 %call20 = tail call i32 @bar(i32 %in2) nounwind 48 switch i32 %call20, label %sw.default56 [ 49 i32 168, label %sw.bb21 50 i32 165, label %sw.bb21 51 i32 261, label %sw.epilog58 52 i32 188, label %sw.epilog58 53 i32 187, label %sw.epilog58 54 i32 186, label %sw.epilog58 55 i32 185, label %sw.epilog58 56 i32 184, label %sw.epilog58 57 i32 175, label %sw.epilog58 58 i32 174, label %sw.epilog58 59 i32 173, label %sw.epilog58 60 i32 172, label %sw.epilog58 61 i32 171, label %sw.epilog58 62 i32 167, label %sw.epilog58 63 i32 166, label %sw.epilog58 64 i32 164, label %sw.epilog58 65 i32 163, label %sw.epilog58 66 i32 161, label %sw.epilog58 67 i32 160, label %sw.epilog58 68 i32 -1, label %sw.bb33 69 ] 70 71 sw.bb21: ; preds = %sw.bb18, %sw.bb18 72 tail call void @foo(i32 %in2) nounwind 73 %call28 = tail call i32 @getint() nounwind 74 %tobool = icmp eq i32 %call28, 0 75 br i1 %tobool, label %if.then29, label %sw.epilog58 76 77 if.then29: ; preds = %sw.bb21 78 tail call void @foo(i32 %in2) nounwind 79 br label %sw.epilog58 80 81 sw.bb33: ; preds = %sw.bb18 82 %cmp42 = tail call zeroext i1 @getbool() nounwind 83 br i1 %cmp42, label %sw.default56, label %land.lhs.true44 84 85 land.lhs.true44: ; preds = %sw.bb33 86 %call50 = tail call i32 @getint() nounwind 87 %cmp51 = icmp slt i32 %call50, 0 88 br i1 %cmp51, label %if.then53, label %sw.default56 89 90 if.then53: ; preds = %land.lhs.true44 91 tail call void @foo(i32 %in2) nounwind 92 br label %sw.default56 93 94 sw.default56: ; preds = %sw.bb33, %land.lhs.true44, %if.then53, %sw.bb18 95 br label %sw.epilog58 96 97 sw.epilog58: 98 %retval.0 = phi i32 [ 4, %sw.default56 ], [ 2, %sw.bb21 ], [ 2, %if.then29 ], [ 2, %sw.bb18 ], [ 2, %sw.bb18 ], [ 2, %sw.bb18 ], [ 2, %sw.bb18 ], [ 2, %sw.bb18 ], [ 2, %sw.bb18 ], [ 2, %sw.bb18 ], [ 2, %sw.bb18 ], [ 2, %sw.bb18 ], [ 2, %sw.bb18 ], [ 2, %sw.bb18 ], [ 2, %sw.bb18 ], [ 2, %sw.bb18 ], [ 2, %sw.bb18 ], [ 2, %sw.bb18 ], [ 2, %sw.bb18 ], [ 2, %sw.bb18 ], [ 2, %sw.bb2 ], [ 2, %land.lhs.true ], [ 2, %if.then ] 99 ret i32 %retval.0 100 } 101
