llvm/test/Transforms/InstCombine/assume-align.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals smart
; RUN: opt -S -passes=instcombine,simplifycfg < %s 2>&1 | FileCheck %s

declare void @llvm.assume(i1 noundef)

define void @f1(ptr %a) {
; CHECK-LABEL: @f1(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[PTR:%.*]] = getelementptr inbounds nuw i8, ptr [[A:%.*]], i64 4
; CHECK-NEXT:    [[TMP0:%.*]] = ptrtoint ptr [[PTR]] to i64
; CHECK-NEXT:    [[TMP1:%.*]] = and i64 [[TMP0]], 3
; CHECK-NEXT:    [[TMP2:%.*]] = icmp eq i64 [[TMP1]], 0
; CHECK-NEXT:    br i1 [[TMP2]], label [[IF_THEN:%.*]], label [[IF_END:%.*]]
; CHECK:       if.then:
; CHECK-NEXT:    call void @llvm.assume(i1 true) [ "align"(ptr [[PTR]], i64 4) ]
; CHECK-NEXT:    store i32 4, ptr [[PTR]], align 4
; CHECK-NEXT:    br label [[IF_END]]
; CHECK:       if.end:
; CHECK-NEXT:    ret void
;
entry:
  %ptr = getelementptr inbounds i8, ptr %a, i64 4
  %0 = ptrtoint ptr %ptr to i64
  %1 = and i64 %0, 3
  %2 = icmp eq i64 %1, 0
  br i1 %2, label %if.then, label %if.end

if.then:                                          ; preds = %entry
  call void @llvm.assume(i1 true) [ "align"(ptr %ptr, i64 4) ]
  %3 = ptrtoint ptr %ptr to i64
  %4 = and i64 %3, 3
  %5 = icmp eq i64 %4, 0
  br i1 %5, label %if.then1, label %if.else1

if.then1:                                         ; preds = %if.then
  store i32 4, ptr %ptr, align 4
  br label %if.end

if.else1:                                         ; preds = %if.then
  store i8 1, ptr %ptr, align 1
  br label %if.end

if.end:                                           ; preds = %if.then1, %if.else1, %entry
  ret void
}

; TODO: We could fold away the branch "br i1 %3, ..." by either using a GEP or make getKnowledgeValidInContext aware the alignment bundle offset, and the improvement of value tracking of GEP.

define void @f2(ptr %a) {
; CHECK-LABEL: @f2(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    call void @llvm.assume(i1 true) [ "align"(ptr [[A:%.*]], i64 32, i32 24) ]
; CHECK-NEXT:    [[TMP0:%.*]] = getelementptr inbounds nuw i8, ptr [[A]], i64 8
; CHECK-NEXT:    [[TMP1:%.*]] = ptrtoint ptr [[TMP0]] to i64
; CHECK-NEXT:    [[TMP2:%.*]] = and i64 [[TMP1]], 8
; CHECK-NEXT:    [[TMP3:%.*]] = icmp eq i64 [[TMP2]], 0
; CHECK-NEXT:    br i1 [[TMP3]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
; CHECK:       if.then:
; CHECK-NEXT:    store i64 16, ptr [[TMP0]], align 4
; CHECK-NEXT:    br label [[IF_END:%.*]]
; CHECK:       if.else:
; CHECK-NEXT:    store i8 1, ptr [[TMP0]], align 1
; CHECK-NEXT:    br label [[IF_END]]
; CHECK:       if.end:
; CHECK-NEXT:    ret void
;
entry:
  call void @llvm.assume(i1 true) [ "align"(ptr %a, i64 32, i32 24) ]
  %0 = getelementptr inbounds i8, ptr %a, i64 8
  %1 = ptrtoint ptr %0 to i64
  %2 = and i64 %1, 15
  %3 = icmp eq i64 %2, 0
  br i1 %3, label %if.then, label %if.else

if.then:                                          ; preds = %entry
  store i64 16, ptr %0, align 4
  br label %if.end

if.else:                                          ; preds = %entry
  store i8 1, ptr %0, align 1
  br label %if.end

if.end:                                           ; preds = %if.else, %if.then
  ret void
}

define void @f3(i64 %a, ptr %b) {
; CHECK-LABEL: @f3(
; CHECK-NEXT:    [[C:%.*]] = ptrtoint ptr [[B:%.*]] to i64
; CHECK-NEXT:    call void @llvm.assume(i1 true) [ "align"(ptr [[B]], i64 4294967296) ]
; CHECK-NEXT:    [[D:%.*]] = add i64 [[A:%.*]], [[C]]
; CHECK-NEXT:    call void @g(i64 [[D]])
; CHECK-NEXT:    ret void
;
  %c = ptrtoint ptr %b to i64
  call void @llvm.assume(i1 true) [ "align"(ptr %b, i64 4294967296) ]
  %d = add i64 %a, %c
  call void @g(i64 %d)
  ret void
}

declare void @g(i64)

define i8 @assume_align_zero(ptr %p) {
; CHECK-LABEL: @assume_align_zero(
; CHECK-NEXT:    call void @llvm.assume(i1 true) [ "align"(ptr [[P:%.*]], i64 0) ]
; CHECK-NEXT:    [[V:%.*]] = load i8, ptr [[P]], align 1
; CHECK-NEXT:    ret i8 [[V]]
;
  call void @llvm.assume(i1 true) [ "align"(ptr %p, i64 0) ]
  %v = load i8, ptr %p
  ret i8 %v
}

define i8 @assume_align_non_pow2(ptr %p) {
; CHECK-LABEL: @assume_align_non_pow2(
; CHECK-NEXT:    call void @llvm.assume(i1 true) [ "align"(ptr [[P:%.*]], i64 123) ]
; CHECK-NEXT:    [[V:%.*]] = load i8, ptr [[P]], align 1
; CHECK-NEXT:    ret i8 [[V]]
;
  call void @llvm.assume(i1 true) [ "align"(ptr %p, i64 123) ]
  %v = load i8, ptr %p
  ret i8 %v
}

; TODO: Can fold alignment assumption into !align metadata on load.
define ptr @fold_assume_align_pow2_of_loaded_pointer_into_align_metadata(ptr %p) {
; CHECK-LABEL: @fold_assume_align_pow2_of_loaded_pointer_into_align_metadata(
; CHECK-NEXT:    [[P2:%.*]] = load ptr, ptr [[P:%.*]], align 8
; CHECK-NEXT:    call void @llvm.assume(i1 true) [ "align"(ptr [[P2]], i64 8) ]
; CHECK-NEXT:    ret ptr [[P2]]
;
  %p2 = load ptr, ptr %p
  call void @llvm.assume(i1 true) [ "align"(ptr %p2, i64 8) ]
  ret ptr %p2
}

define ptr @dont_fold_assume_align_pow2_of_loaded_pointer_into_align_metadata_due_to_call(ptr %p) {
; CHECK-LABEL: @dont_fold_assume_align_pow2_of_loaded_pointer_into_align_metadata_due_to_call(
; CHECK-NEXT:    [[P2:%.*]] = load ptr, ptr [[P:%.*]], align 8
; CHECK-NEXT:    call void @g(i64 0)
; CHECK-NEXT:    call void @llvm.assume(i1 true) [ "align"(ptr [[P2]], i64 8) ]
; CHECK-NEXT:    ret ptr [[P2]]
;
  %p2 = load ptr, ptr %p
  call void @g(i64 0)
  call void @llvm.assume(i1 true) [ "align"(ptr %p2, i64 8) ]
  ret ptr %p2
}

; !align must have a power-of-2 alignment.
define ptr @dont_fold_assume_align_non_pow2_of_loaded_pointer_into_align_metadata(ptr %p) {
; CHECK-LABEL: @dont_fold_assume_align_non_pow2_of_loaded_pointer_into_align_metadata(
; CHECK-NEXT:    [[P2:%.*]] = load ptr, ptr [[P:%.*]], align 8
; CHECK-NEXT:    call void @llvm.assume(i1 true) [ "align"(ptr [[P2]], i64 13) ]
; CHECK-NEXT:    ret ptr [[P2]]
;
  %p2 = load ptr, ptr %p
  call void @llvm.assume(i1 true) [ "align"(ptr %p2, i64 13) ]
  ret ptr %p2
}

; !align must have a power-of-2 alignment.
define ptr @dont_fold_assume_align_zero_of_loaded_pointer_into_align_metadata(ptr %p) {
; CHECK-LABEL: @dont_fold_assume_align_zero_of_loaded_pointer_into_align_metadata(
; CHECK-NEXT:    [[P2:%.*]] = load ptr, ptr [[P:%.*]], align 8
; CHECK-NEXT:    call void @llvm.assume(i1 true) [ "align"(ptr [[P2]], i64 0) ]
; CHECK-NEXT:    ret ptr [[P2]]
;
  %p2 = load ptr, ptr %p
  call void @llvm.assume(i1 true) [ "align"(ptr %p2, i64 0) ]
  ret ptr %p2
}

define ptr @redundant_assume_align_1(ptr %p) {
; CHECK-LABEL: @redundant_assume_align_1(
; CHECK-NEXT:    [[P2:%.*]] = load ptr, ptr [[P:%.*]], align 8
; CHECK-NEXT:    call void @llvm.assume(i1 true) [ "align"(ptr [[P2]], i32 1) ]
; CHECK-NEXT:    call void @foo(ptr [[P2]])
; CHECK-NEXT:    ret ptr [[P2]]
;
  %p2 = load ptr, ptr %p
  call void @llvm.assume(i1 true) [ "align"(ptr %p2, i32 1) ]
  call void @foo(ptr %p2)
  ret ptr %p2
}


define ptr @redundant_assume_align_8_via_align_metadata(ptr %p) {
; CHECK-LABEL: @redundant_assume_align_8_via_align_metadata(
; CHECK-NEXT:    [[P2:%.*]] = load ptr, ptr [[P:%.*]], align 8, !align [[META0:![0-9]+]]
; CHECK-NEXT:    call void @llvm.assume(i1 true) [ "align"(ptr [[P2]], i32 8) ]
; CHECK-NEXT:    call void @foo(ptr [[P2]])
; CHECK-NEXT:    ret ptr [[P2]]
;
  %p2 = load ptr, ptr %p, !align !{i64 8}
  call void @llvm.assume(i1 true) [ "align"(ptr %p2, i32 8) ]
  call void @foo(ptr %p2)
  ret ptr %p2
}

define ptr @assume_align_16_via_align_metadata(ptr %p) {
; CHECK-LABEL: @assume_align_16_via_align_metadata(
; CHECK-NEXT:    [[P2:%.*]] = load ptr, ptr [[P:%.*]], align 8, !align [[META0]]
; CHECK-NEXT:    call void @llvm.assume(i1 true) [ "align"(ptr [[P2]], i32 16) ]
; CHECK-NEXT:    call void @foo(ptr [[P2]])
; CHECK-NEXT:    ret ptr [[P2]]
;
  %p2 = load ptr, ptr %p, !align !{i64 8}
  call void @llvm.assume(i1 true) [ "align"(ptr %p2, i32 16) ]
  call void @foo(ptr %p2)
  ret ptr %p2
}

define ptr @redundant_assume_align_8_via_align_attribute(ptr align 8 %p) {
; CHECK-LABEL: @redundant_assume_align_8_via_align_attribute(
; CHECK-NEXT:    call void @llvm.assume(i1 true) [ "align"(ptr [[P:%.*]], i32 8) ]
; CHECK-NEXT:    call void @foo(ptr [[P]])
; CHECK-NEXT:    ret ptr [[P]]
;
  call void @llvm.assume(i1 true) [ "align"(ptr %p, i32 8) ]
  call void @foo(ptr %p)
  ret ptr %p
}

define ptr @assume_align_16_via_align_attribute(ptr align 8 %p) {
; CHECK-LABEL: @assume_align_16_via_align_attribute(
; CHECK-NEXT:    call void @llvm.assume(i1 true) [ "align"(ptr [[P:%.*]], i32 16) ]
; CHECK-NEXT:    call void @foo(ptr [[P]])
; CHECK-NEXT:    ret ptr [[P]]
;
  call void @llvm.assume(i1 true) [ "align"(ptr %p, i32 16) ]
  call void @foo(ptr %p)
  ret ptr %p
}

define ptr @redundant_assume_align_8_via_asume(ptr %p) {
; CHECK-LABEL: @redundant_assume_align_8_via_asume(
; CHECK-NEXT:    call void @llvm.assume(i1 true) [ "align"(ptr [[P:%.*]], i32 16) ]
; CHECK-NEXT:    call void @foo(ptr [[P]])
; CHECK-NEXT:    call void @llvm.assume(i1 true) [ "align"(ptr [[P]], i32 8) ]
; CHECK-NEXT:    call void @foo(ptr [[P]])
; CHECK-NEXT:    ret ptr [[P]]
;
  call void @llvm.assume(i1 true) [ "align"(ptr %p, i32 16) ]
  call void @foo(ptr %p)
  call void @llvm.assume(i1 true) [ "align"(ptr %p, i32 8) ]
  call void @foo(ptr %p)
  ret ptr %p
}

declare void @foo(ptr)
;.
; CHECK: [[META0]] = !{i64 8}
;.