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llvm-project/llvm/test/Transforms/GuardWidening/range-check-merging.ll

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[GuardWidening] Introduce range check merging Sequences of range checks expressed using guards, like guard((I - 2) u< L) guard((I - 1) u< L) guard((I + 0) u< L) guard((I + 1) u< L) guard((I + 2) u< L) can sometimes be combined into a smaller sequence: guard((I - 2) u< L AND (I + 2) u< L) if we can prove that (I - 2) u< L AND (I + 2) u< L implies all of checks expressed in the previous sequence. This change teaches GuardWidening to do this kind of merging when feasible. llvm-svn: 270151
2016-05-20 06:55:46 +08:00
; RUN: opt -S -guard-widening < %s | FileCheck %s
declare void @llvm.experimental.guard(i1,...)
define void @f_0(i32 %x, i32* %length_buf) {
; CHECK-LABEL: @f_0(
; CHECK-NOT: @llvm.experimental.guard
; CHECK: %wide.chk2 = and i1 %chk3, %chk0
; CHECK: call void (i1, ...) @llvm.experimental.guard(i1 %wide.chk2) [ "deopt"() ]
; CHECK: ret void
entry:
%length = load i32, i32* %length_buf, !range !0
%chk0 = icmp ult i32 %x, %length
call void(i1, ...) @llvm.experimental.guard(i1 %chk0) [ "deopt"() ]
%x.inc1 = add i32 %x, 1
%chk1 = icmp ult i32 %x.inc1, %length
call void(i1, ...) @llvm.experimental.guard(i1 %chk1) [ "deopt"() ]
%x.inc2 = add i32 %x, 2
%chk2 = icmp ult i32 %x.inc2, %length
call void(i1, ...) @llvm.experimental.guard(i1 %chk2) [ "deopt"() ]
%x.inc3 = add i32 %x, 3
%chk3 = icmp ult i32 %x.inc3, %length
call void(i1, ...) @llvm.experimental.guard(i1 %chk3) [ "deopt"() ]
ret void
}
define void @f_1(i32 %x, i32* %length_buf) {
; CHECK-LABEL: @f_1(
; CHECK-NOT: llvm.experimental.guard
; CHECK: %wide.chk2 = and i1 %chk3, %chk0
; CHECK: call void (i1, ...) @llvm.experimental.guard(i1 %wide.chk2) [ "deopt"() ]
; CHECK: ret void
entry:
%length = load i32, i32* %length_buf, !range !0
%chk0 = icmp ult i32 %x, %length
call void(i1, ...) @llvm.experimental.guard(i1 %chk0) [ "deopt"() ]
%x.inc1 = add i32 %x, 1
%chk1 = icmp ult i32 %x.inc1, %length
call void(i1, ...) @llvm.experimental.guard(i1 %chk1) [ "deopt"() ]
%x.inc2 = add i32 %x.inc1, 2
%chk2 = icmp ult i32 %x.inc2, %length
call void(i1, ...) @llvm.experimental.guard(i1 %chk2) [ "deopt"() ]
%x.inc3 = add i32 %x.inc2, 3
%chk3 = icmp ult i32 %x.inc3, %length
call void(i1, ...) @llvm.experimental.guard(i1 %chk3) [ "deopt"() ]
ret void
}
define void @f_2(i32 %a, i32* %length_buf) {
; CHECK-LABEL: @f_2(
; CHECK-NOT: llvm.experimental.guard
; CHECK: %wide.chk2 = and i1 %chk3, %chk0
; CHECK: call void (i1, ...) @llvm.experimental.guard(i1 %wide.chk2) [ "deopt"() ]
; CHECK: ret void
entry:
%x = and i32 %a, 4294967040 ;; 4294967040 == 0xffffff00
%length = load i32, i32* %length_buf, !range !0
%chk0 = icmp ult i32 %x, %length
call void(i1, ...) @llvm.experimental.guard(i1 %chk0) [ "deopt"() ]
%x.inc1 = or i32 %x, 1
%chk1 = icmp ult i32 %x.inc1, %length
call void(i1, ...) @llvm.experimental.guard(i1 %chk1) [ "deopt"() ]
%x.inc2 = or i32 %x, 2
%chk2 = icmp ult i32 %x.inc2, %length
call void(i1, ...) @llvm.experimental.guard(i1 %chk2) [ "deopt"() ]
%x.inc3 = or i32 %x, 3
%chk3 = icmp ult i32 %x.inc3, %length
call void(i1, ...) @llvm.experimental.guard(i1 %chk3) [ "deopt"() ]
ret void
}
define void @f_3(i32 %a, i32* %length_buf) {
; CHECK-LABEL: @f_3(
; CHECK-NOT: llvm.experimental.guard
; CHECK: %wide.chk2 = and i1 %chk3, %chk0
; CHECK: call void (i1, ...) @llvm.experimental.guard(i1 %wide.chk2) [ "deopt"() ]
; CHECK: ret void
entry:
%x = and i32 %a, 4294967040 ;; 4294967040 == 0xffffff00
%length = load i32, i32* %length_buf, !range !0
%chk0 = icmp ult i32 %x, %length
call void(i1, ...) @llvm.experimental.guard(i1 %chk0) [ "deopt"() ]
%x.inc1 = add i32 %x, 1
%chk1 = icmp ult i32 %x.inc1, %length
call void(i1, ...) @llvm.experimental.guard(i1 %chk1) [ "deopt"() ]
%x.inc2 = or i32 %x.inc1, 2
%chk2 = icmp ult i32 %x.inc2, %length
call void(i1, ...) @llvm.experimental.guard(i1 %chk2) [ "deopt"() ]
%x.inc3 = add i32 %x.inc2, 3
%chk3 = icmp ult i32 %x.inc3, %length
call void(i1, ...) @llvm.experimental.guard(i1 %chk3) [ "deopt"() ]
ret void
}
define void @f_4(i32 %x, i32* %length_buf) {
; CHECK-LABEL: @f_4(
; CHECK-NOT: llvm.experimental.guard
; Note: we NOT guarding on "and i1 %chk3, %chk0", that would be incorrect.
; CHECK: %wide.chk2 = and i1 %chk3, %chk1
; CHECK: call void (i1, ...) @llvm.experimental.guard(i1 %wide.chk2) [ "deopt"() ]
; CHECK: ret void
entry:
%length = load i32, i32* %length_buf, !range !0
%chk0 = icmp ult i32 %x, %length
call void(i1, ...) @llvm.experimental.guard(i1 %chk0) [ "deopt"() ]
%x.inc1 = add i32 %x, -1024
%chk1 = icmp ult i32 %x.inc1, %length
call void(i1, ...) @llvm.experimental.guard(i1 %chk1) [ "deopt"() ]
%x.inc2 = add i32 %x, 2
%chk2 = icmp ult i32 %x.inc2, %length
call void(i1, ...) @llvm.experimental.guard(i1 %chk2) [ "deopt"() ]
%x.inc3 = add i32 %x, 3
%chk3 = icmp ult i32 %x.inc3, %length
call void(i1, ...) @llvm.experimental.guard(i1 %chk3) [ "deopt"() ]
ret void
}
define void @f_5(i32 %x, i32* %length_buf) {
; CHECK-LABEL: @f_5(
; CHECK-NOT: llvm.experimental.guard
; CHECK: %wide.chk2 = and i1 %chk1, %chk2
; CHECK: call void (i1, ...) @llvm.experimental.guard(i1 %wide.chk2) [ "deopt"() ]
; CHECK: ret void
entry:
%length = load i32, i32* %length_buf, !range !0
%chk0 = icmp ult i32 %x, %length
call void(i1, ...) @llvm.experimental.guard(i1 %chk0) [ "deopt"() ]
%x.inc1 = add i32 %x, 1
%chk1 = icmp ult i32 %x.inc1, %length
call void(i1, ...) @llvm.experimental.guard(i1 %chk1) [ "deopt"() ]
%x.inc2 = add i32 %x.inc1, -200
%chk2 = icmp ult i32 %x.inc2, %length
call void(i1, ...) @llvm.experimental.guard(i1 %chk2) [ "deopt"() ]
%x.inc3 = add i32 %x.inc2, 3
%chk3 = icmp ult i32 %x.inc3, %length
call void(i1, ...) @llvm.experimental.guard(i1 %chk3) [ "deopt"() ]
ret void
}
; Negative test: we can't merge these checks into
;
; (%x + -2147483647) u< L && (%x + 3) u< L
;
; because if %length == INT_MAX and %x == -3 then
;
; (%x + -2147483647) == i32 2147483646 u< L (L is 2147483647)
; (%x + 3) == 0 u< L
;
; But (%x + 2) == -1 is not u< L
;
define void @f_6(i32 %x, i32* %length_buf) {
; CHECK-LABEL: @f_6(
; CHECK-NOT: llvm.experimental.guard
; CHECK: %wide.chk = and i1 %chk0, %chk1
; CHECK: %wide.chk1 = and i1 %wide.chk, %chk2
; CHECK: %wide.chk2 = and i1 %wide.chk1, %chk3
; CHECK: call void (i1, ...) @llvm.experimental.guard(i1 %wide.chk2) [ "deopt"() ]
entry:
%length = load i32, i32* %length_buf, !range !0
%chk0 = icmp ult i32 %x, %length
call void(i1, ...) @llvm.experimental.guard(i1 %chk0) [ "deopt"() ]
%x.inc1 = add i32 %x, -2147483647 ;; -2147483647 == (i32 INT_MIN)+1 == -(i32 INT_MAX)
%chk1 = icmp ult i32 %x.inc1, %length
call void(i1, ...) @llvm.experimental.guard(i1 %chk1) [ "deopt"() ]
%x.inc2 = add i32 %x, 2
%chk2 = icmp ult i32 %x.inc2, %length
call void(i1, ...) @llvm.experimental.guard(i1 %chk2) [ "deopt"() ]
%x.inc3 = add i32 %x, 3
%chk3 = icmp ult i32 %x.inc3, %length
call void(i1, ...) @llvm.experimental.guard(i1 %chk3) [ "deopt"() ]
ret void
}
[GuardWidening] Fix incorrect use of remove_if I had used `std::remove_if` under the assumption that it moves the predicate matching elements to the end, but actaully the elements remaining towards the end (after the iterator returned by `std::remove_if`) are indeterminate. Fix the bug (and make the code more straightforward) by using a temporary SmallVector, and add a test case demonstrating the issue. llvm-svn: 270306
2016-05-21 10:24:44 +08:00
define void @f_7(i32 %x, i32* %length_buf) {
; CHECK-LABEL: @f_7(
; CHECK: [[COND_0:%[^ ]+]] = and i1 %chk3.b, %chk0.b
; CHECK: [[COND_1:%[^ ]+]] = and i1 %chk0.a, [[COND_0]]
; CHECK: [[COND_2:%[^ ]+]] = and i1 %chk3.a, [[COND_1]]
; CHECK: call void (i1, ...) @llvm.experimental.guard(i1 [[COND_2]]) [ "deopt"() ]
entry:
%length_a = load volatile i32, i32* %length_buf, !range !0
%length_b = load volatile i32, i32* %length_buf, !range !0
%chk0.a = icmp ult i32 %x, %length_a
%chk0.b = icmp ult i32 %x, %length_b
%chk0 = and i1 %chk0.a, %chk0.b
call void(i1, ...) @llvm.experimental.guard(i1 %chk0) [ "deopt"() ]
%x.inc1 = add i32 %x, 1
%chk1.a = icmp ult i32 %x.inc1, %length_a
%chk1.b = icmp ult i32 %x.inc1, %length_b
%chk1 = and i1 %chk1.a, %chk1.b
call void(i1, ...) @llvm.experimental.guard(i1 %chk1) [ "deopt"() ]
%x.inc2 = add i32 %x, 2
%chk2.a = icmp ult i32 %x.inc2, %length_a
%chk2.b = icmp ult i32 %x.inc2, %length_b
%chk2 = and i1 %chk2.a, %chk2.b
call void(i1, ...) @llvm.experimental.guard(i1 %chk2) [ "deopt"() ]
%x.inc3 = add i32 %x, 3
%chk3.a = icmp ult i32 %x.inc3, %length_a
%chk3.b = icmp ult i32 %x.inc3, %length_b
%chk3 = and i1 %chk3.a, %chk3.b
call void(i1, ...) @llvm.experimental.guard(i1 %chk3) [ "deopt"() ]
ret void
}
[GuardWidening] Introduce range check merging Sequences of range checks expressed using guards, like guard((I - 2) u< L) guard((I - 1) u< L) guard((I + 0) u< L) guard((I + 1) u< L) guard((I + 2) u< L) can sometimes be combined into a smaller sequence: guard((I - 2) u< L AND (I + 2) u< L) if we can prove that (I - 2) u< L AND (I + 2) u< L implies all of checks expressed in the previous sequence. This change teaches GuardWidening to do this kind of merging when feasible. llvm-svn: 270151
2016-05-20 06:55:46 +08:00
!0 = !{i32 0, i32 2147483648}