1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py 2; RUN: opt < %s -passes=instcombine -S -data-layout="e-n16:32:64" | FileCheck %s 3; RUN: opt < %s -passes=instcombine -S -data-layout="E-n16:32:64" | FileCheck %s 4 5; Don't narrow if it would lose information about the dereferenceable range of the pointer. 6 7define i32 @truncload_no_deref(ptr %ptr) { 8; CHECK-LABEL: @truncload_no_deref( 9; CHECK-NEXT: [[X:%.*]] = load i64, ptr [[PTR:%.*]], align 4 10; CHECK-NEXT: [[R:%.*]] = trunc i64 [[X]] to i32 11; CHECK-NEXT: ret i32 [[R]] 12; 13 %x = load i64, ptr %ptr 14 %r = trunc i64 %x to i32 15 ret i32 %r 16} 17 18define i32 @truncload_small_deref(ptr dereferenceable(7) %ptr) { 19; CHECK-LABEL: @truncload_small_deref( 20; CHECK-NEXT: [[X:%.*]] = load i64, ptr [[PTR:%.*]], align 4 21; CHECK-NEXT: [[R:%.*]] = trunc i64 [[X]] to i32 22; CHECK-NEXT: ret i32 [[R]] 23; 24 %x = load i64, ptr %ptr 25 %r = trunc i64 %x to i32 26 ret i32 %r 27} 28 29; On little-endian, we can narrow the load without an offset. 30 31define i32 @truncload_deref(ptr dereferenceable(8) %ptr) { 32; CHECK-LABEL: @truncload_deref( 33; CHECK-NEXT: [[X:%.*]] = load i64, ptr [[PTR:%.*]], align 4 34; CHECK-NEXT: [[R:%.*]] = trunc i64 [[X]] to i32 35; CHECK-NEXT: ret i32 [[R]] 36; 37 %x = load i64, ptr %ptr 38 %r = trunc i64 %x to i32 39 ret i32 %r 40} 41 42; Preserve alignment. 43 44define i16 @truncload_align(ptr dereferenceable(14) %ptr) { 45; CHECK-LABEL: @truncload_align( 46; CHECK-NEXT: [[X:%.*]] = load i32, ptr [[PTR:%.*]], align 16 47; CHECK-NEXT: [[R:%.*]] = trunc i32 [[X]] to i16 48; CHECK-NEXT: ret i16 [[R]] 49; 50 %x = load i32, ptr %ptr, align 16 51 %r = trunc i32 %x to i16 52 ret i16 %r 53} 54 55; Negative test - extra use means we would not eliminate the original load. 56 57declare void @use(i64) 58 59define i32 @truncload_extra_use(ptr dereferenceable(100) %ptr) { 60; CHECK-LABEL: @truncload_extra_use( 61; CHECK-NEXT: [[X:%.*]] = load i64, ptr [[PTR:%.*]], align 2 62; CHECK-NEXT: call void @use(i64 [[X]]) 63; CHECK-NEXT: [[R:%.*]] = trunc i64 [[X]] to i32 64; CHECK-NEXT: ret i32 [[R]] 65; 66 %x = load i64, ptr %ptr, align 2 67 call void @use(i64 %x) 68 %r = trunc i64 %x to i32 69 ret i32 %r 70} 71 72; Negative test - don't create a load if the type is not allowed by the data-layout. 73 74define i8 @truncload_type(ptr dereferenceable(9) %ptr) { 75; CHECK-LABEL: @truncload_type( 76; CHECK-NEXT: [[X:%.*]] = load i64, ptr [[PTR:%.*]], align 2 77; CHECK-NEXT: [[R:%.*]] = trunc i64 [[X]] to i8 78; CHECK-NEXT: ret i8 [[R]] 79; 80 %x = load i64, ptr %ptr, align 2 81 %r = trunc i64 %x to i8 82 ret i8 %r 83} 84 85; Negative test - don't transform volatiles. 86 87define i32 @truncload_volatile(ptr dereferenceable(8) %ptr) { 88; CHECK-LABEL: @truncload_volatile( 89; CHECK-NEXT: [[X:%.*]] = load volatile i64, ptr [[PTR:%.*]], align 8 90; CHECK-NEXT: [[R:%.*]] = trunc i64 [[X]] to i32 91; CHECK-NEXT: ret i32 [[R]] 92; 93 %x = load volatile i64, ptr %ptr, align 8 94 %r = trunc i64 %x to i32 95 ret i32 %r 96} 97 98; Preserve address space. 99 100define i32 @truncload_address_space(ptr addrspace(1) dereferenceable(8) %ptr) { 101; CHECK-LABEL: @truncload_address_space( 102; CHECK-NEXT: [[X:%.*]] = load i64, ptr addrspace(1) [[PTR:%.*]], align 4 103; CHECK-NEXT: [[R:%.*]] = trunc i64 [[X]] to i32 104; CHECK-NEXT: ret i32 [[R]] 105; 106 %x = load i64, ptr addrspace(1) %ptr, align 4 107 %r = trunc i64 %x to i32 108 ret i32 %r 109} 110