1; RUN: llc < %s -mtriple=arm-apple-darwin | FileCheck %s 2 3define i32 @f(i32 %a, i32 %b) nounwind ssp { 4entry: 5; CHECK-LABEL: f: 6; CHECK: subs 7; CHECK-NOT: cmp 8 %cmp = icmp sgt i32 %a, %b 9 %sub = sub nsw i32 %a, %b 10 %sub. = select i1 %cmp, i32 %sub, i32 0 11 ret i32 %sub. 12} 13 14define i32 @g(i32 %a, i32 %b) nounwind ssp { 15entry: 16; CHECK-LABEL: g: 17; CHECK: subs 18; CHECK-NOT: cmp 19 %cmp = icmp slt i32 %a, %b 20 %sub = sub nsw i32 %b, %a 21 %sub. = select i1 %cmp, i32 %sub, i32 0 22 ret i32 %sub. 23} 24 25define i32 @h(i32 %a, i32 %b) nounwind ssp { 26entry: 27; CHECK-LABEL: h: 28; CHECK: subs 29; CHECK-NOT: cmp 30 %cmp = icmp sgt i32 %a, 3 31 %sub = sub nsw i32 %a, 3 32 %sub. = select i1 %cmp, i32 %sub, i32 %b 33 ret i32 %sub. 34} 35 36; rdar://11725965 37define i32 @i(i32 %a, i32 %b) nounwind readnone ssp { 38entry: 39; CHECK-LABEL: i: 40; CHECK: subs 41; CHECK-NOT: cmp 42 %cmp = icmp ult i32 %a, %b 43 %sub = sub i32 %b, %a 44 %sub. = select i1 %cmp, i32 %sub, i32 0 45 ret i32 %sub. 46} 47; If CPSR is live-out, we can't remove cmp if there exists 48; a swapped sub. 49define i32 @j(i32 %a, i32 %b) nounwind { 50entry: 51; CHECK-LABEL: j: 52; CHECK: sub 53; CHECK: cmp 54 %cmp = icmp eq i32 %b, %a 55 %sub = sub nsw i32 %a, %b 56 br i1 %cmp, label %if.then, label %if.else 57 58if.then: 59 %cmp2 = icmp sgt i32 %b, %a 60 %sel = select i1 %cmp2, i32 %sub, i32 %a 61 ret i32 %sel 62 63if.else: 64 ret i32 %sub 65} 66 67; If the sub/rsb instruction is predicated, we can't use the flags. 68; <rdar://problem/12263428> 69; Test case from MultiSource/Benchmarks/Ptrdist/bc/number.s 70; CHECK: bc_raise 71; CHECK: rsbeq 72; CHECK: cmp 73define i32 @bc_raise() nounwind ssp { 74entry: 75 %val.2.i = select i1 undef, i32 0, i32 undef 76 %sub.i = sub nsw i32 0, %val.2.i 77 %retval.0.i = select i1 undef, i32 %val.2.i, i32 %sub.i 78 %cmp1 = icmp eq i32 %retval.0.i, 0 79 br i1 %cmp1, label %land.lhs.true, label %if.end11 80 81land.lhs.true: ; preds = %num2long.exit 82 ret i32 17 83 84if.end11: ; preds = %num2long.exit 85 ret i32 23 86} 87