1; RUN: llc -march=x86-64 < %s | FileCheck %s 2 3target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64" 4target triple = "x86_64-pc-linux-gnu" 5 6; DAGCombiner should fold this code in finite time. 7; rdar://8606584 8 9define void @test1() nounwind readnone { 10bb.nph: 11 br label %while.cond 12 13while.cond: ; preds = %while.cond, %bb.nph 14 %tmp6 = load i32, i32* undef, align 4 15 %and = or i64 undef, undef 16 %conv11 = zext i32 undef to i64 17 %conv14 = zext i32 %tmp6 to i64 18 %shl15 = shl i64 %conv14, 1 19 %shl15.masked = and i64 %shl15, 4294967294 20 %and17 = or i64 %shl15.masked, %conv11 21 %add = add i64 %and17, 1 22 %xor = xor i64 %add, %and 23 %tmp20 = load i64, i64* undef, align 8 24 %add21 = add i64 %xor, %tmp20 25 %conv22 = trunc i64 %add21 to i32 26 store i32 %conv22, i32* undef, align 4 27 br i1 false, label %while.end, label %while.cond 28 29while.end: ; preds = %while.cond 30 ret void 31} 32 33; DAG Combiner can't fold this into a load of the 1'th byte. 34; PR8757 35define i32 @test3(i32 *%P) nounwind ssp { 36 store volatile i32 128, i32* %P 37 %tmp4.pre = load i32, i32* %P 38 %phitmp = trunc i32 %tmp4.pre to i16 39 %phitmp13 = shl i16 %phitmp, 8 40 %phitmp14 = ashr i16 %phitmp13, 8 41 %phitmp15 = lshr i16 %phitmp14, 8 42 %phitmp16 = zext i16 %phitmp15 to i32 43 ret i32 %phitmp16 44 45; CHECK: movl $128, (%rdi) 46; CHECK-NEXT: movsbl (%rdi), %eax 47; CHECK-NEXT: movzbl %ah, %eax 48; CHECK-NEXT: ret 49} 50