1 ; RUN: llc -mtriple=aarch64-linux-gnu -mcpu=cortex-a57 -verify-machineinstrs < %s | FileCheck %s 2 3 ; CHECK-LABEL: f_XX: 4 ; CHECK: cbz x[[REG:[0-9]+]], [[BB:.LBB.*]] 5 ; CHECK: [[BB]]: 6 ; CHECK-NOT: mov x[[REG]], xzr 7 define i64 @f_XX(i64 %n, i64* nocapture readonly %P) { 8 entry: 9 %tobool = icmp eq i64 %n, 0 10 br i1 %tobool, label %if.end, label %if.then 11 12 if.then: ; preds = %entry 13 %0 = load i64, i64* %P 14 br label %if.end 15 16 if.end: ; preds = %entry, %if.then 17 %a.0 = phi i64 [ %0, %if.then ], [ 0, %entry ] 18 ret i64 %a.0 19 } 20 21 ; CHECK-LABEL: f_WW: 22 ; CHECK: cbz w[[REG:[0-9]+]], [[BB:.LBB.*]] 23 ; CHECK: [[BB]]: 24 ; CHECK-NOT: mov w[[REG]], wzr 25 define i32 @f_WW(i32 %n, i32* nocapture readonly %P) { 26 entry: 27 %tobool = icmp eq i32 %n, 0 28 br i1 %tobool, label %if.end, label %if.then 29 30 if.then: ; preds = %entry 31 %0 = load i32, i32* %P 32 br label %if.end 33 34 if.end: ; preds = %entry, %if.then 35 %a.0 = phi i32 [ %0, %if.then ], [ 0, %entry ] 36 ret i32 %a.0 37 } 38 39 ; CHECK-LABEL: f_XW: 40 ; CHECK: cbz x[[REG:[0-9]+]], [[BB:.LBB.*]] 41 ; CHECK: [[BB]]: 42 ; CHECK-NOT: mov w[[REG]], wzr 43 define i32 @f_XW(i64 %n, i32* nocapture readonly %P) { 44 entry: 45 %tobool = icmp eq i64 %n, 0 46 br i1 %tobool, label %if.end, label %if.then 47 48 if.then: ; preds = %entry 49 %0 = load i32, i32* %P 50 br label %if.end 51 52 if.end: ; preds = %entry, %if.then 53 %a.0 = phi i32 [ %0, %if.then ], [ 0, %entry ] 54 ret i32 %a.0 55 } 56 57 ; CHECK-LABEL: f_WX: 58 ; CHECK: cbz w[[REG:[0-9]+]], [[BB:.LBB.*]] 59 ; CHECK: [[BB]]: 60 ; CHECK: mov x[[REG]], xzr 61 ; Do not remove the mov in this case because we do not know if the upper bits 62 ; of the X register are zero. 63 define i64 @f_WX(i32 %n, i64* nocapture readonly %P) { 64 entry: 65 %tobool = icmp eq i32 %n, 0 66 br i1 %tobool, label %if.end, label %if.then 67 68 if.then: ; preds = %entry 69 %0 = load i64, i64* %P 70 br label %if.end 71 72 if.end: ; preds = %entry, %if.then 73 %a.0 = phi i64 [ %0, %if.then ], [ 0, %entry ] 74 ret i64 %a.0 75 } 76 77 ; CHECK-LABEL: test_superreg: 78 ; CHECK: cbz x[[REG:[0-9]+]], [[BB:.LBB.*]] 79 ; CHECK: [[BB]]: 80 ; CHECK: str x[[REG]], [x1] 81 ; CHECK-NOT: mov w[[REG]], wzr 82 ; Because we returned w0 but x0 was marked live-in to the block, we didn't 83 ; remove the <kill> on the str leading to a verification failure. 84 define i32 @test_superreg(i64 %in, i64* %dest) { 85 %tst = icmp eq i64 %in, 0 86 br i1 %tst, label %true, label %false 87 88 false: 89 ret i32 42 90 91 true: 92 store volatile i64 %in, i64* %dest 93 ret i32 0 94 } 95
