Files
clang-p2996/llvm/test/CodeGen/X86/implicit-null-check.ll
Yichao Yu a18b0b1817 Fix implicit null check with negative offset
Summary:
It seems that negative offset was accidentally allowed in D17967.
AFAICT small negative offset should be valid (always raise segfault) on all archs that I'm aware of (especially x86, which is the only one with this optimization enabled) and such case can be useful when loading hiden metadata from an object.

However, like the positive side, it should only be done within a certain limit.
For now, use the same limit on the positive side for the negative side.
A separate option can be added if needs appear.

Reviewers: mcrosier, skatkov

Reviewed By: skatkov

Subscribers: sanjoy, llvm-commits

Differential Revision: https://reviews.llvm.org/D38925

llvm-svn: 315991
2017-10-17 11:47:36 +00:00

344 lines
9.6 KiB
LLVM

; RUN: llc -verify-machineinstrs -O3 -mtriple=x86_64-apple-macosx -enable-implicit-null-checks < %s | FileCheck %s
; RUN: llc < %s -mtriple=x86_64-apple-macosx -enable-implicit-null-checks \
; RUN: | llvm-mc -triple x86_64-apple-macosx -filetype=obj -o - \
; RUN: | llvm-objdump -triple x86_64-apple-macosx -fault-map-section - \
; RUN: | FileCheck %s -check-prefix OBJDUMP
; RUN: llc < %s -mtriple=x86_64-unknown-linux-gnu -enable-implicit-null-checks \
; RUN: | llvm-mc -triple x86_64-unknown-linux-gnu -filetype=obj -o - \
; RUN: | llvm-objdump -triple x86_64-unknown-linux-gnu -fault-map-section - \
; RUN: | FileCheck %s -check-prefix OBJDUMP
define i32 @imp_null_check_load(i32* %x) {
; CHECK-LABEL: _imp_null_check_load:
; CHECK: [[BB0_imp_null_check_load:L[^:]+]]:
; CHECK: movl (%rdi), %eax
; CHECK: retq
; CHECK: [[BB1_imp_null_check_load:LBB0_[0-9]+]]:
; CHECK: movl $42, %eax
; CHECK: retq
entry:
%c = icmp eq i32* %x, null
br i1 %c, label %is_null, label %not_null, !make.implicit !0
is_null:
ret i32 42
not_null:
%t = load i32, i32* %x
ret i32 %t
}
define i32 @imp_null_check_gep_load(i32* %x) {
; CHECK-LABEL: _imp_null_check_gep_load:
; CHECK: [[BB0_imp_null_check_gep_load:L[^:]+]]:
; CHECK: movl 128(%rdi), %eax
; CHECK: retq
; CHECK: [[BB1_imp_null_check_gep_load:LBB1_[0-9]+]]:
; CHECK: movl $42, %eax
; CHECK: retq
entry:
%c = icmp eq i32* %x, null
br i1 %c, label %is_null, label %not_null, !make.implicit !0
is_null:
ret i32 42
not_null:
%x.gep = getelementptr i32, i32* %x, i32 32
%t = load i32, i32* %x.gep
ret i32 %t
}
define i32 @imp_null_check_add_result(i32* %x, i32 %p) {
; CHECK-LABEL: _imp_null_check_add_result:
; CHECK: [[BB0_imp_null_check_add_result:L[^:]+]]:
; CHECK: addl (%rdi), %esi
; CHECK: movl %esi, %eax
; CHECK: retq
; CHECK: [[BB1_imp_null_check_add_result:LBB2_[0-9]+]]:
; CHECK: movl $42, %eax
; CHECK: retq
entry:
%c = icmp eq i32* %x, null
br i1 %c, label %is_null, label %not_null, !make.implicit !0
is_null:
ret i32 42
not_null:
%t = load i32, i32* %x
%p1 = add i32 %t, %p
ret i32 %p1
}
define i32 @imp_null_check_hoist_over_unrelated_load(i32* %x, i32* %y, i32* %z) {
; CHECK-LABEL: _imp_null_check_hoist_over_unrelated_load:
; CHECK: [[BB0_imp_null_check_hoist_over_unrelated_load:L[^:]+]]:
; CHECK: movl (%rdi), %eax
; CHECK: movl (%rsi), %ecx
; CHECK: movl %ecx, (%rdx)
; CHECK: retq
; CHECK: [[BB1_imp_null_check_hoist_over_unrelated_load:LBB3_[0-9]+]]:
; CHECK: movl $42, %eax
; CHECK: retq
entry:
%c = icmp eq i32* %x, null
br i1 %c, label %is_null, label %not_null, !make.implicit !0
is_null:
ret i32 42
not_null:
%t0 = load i32, i32* %y
%t1 = load i32, i32* %x
store i32 %t0, i32* %z
ret i32 %t1
}
define i32 @imp_null_check_via_mem_comparision(i32* %x, i32 %val) {
; CHECK-LABEL: _imp_null_check_via_mem_comparision
; CHECK: [[BB0_imp_null_check_via_mem_comparision:L[^:]+]]:
; CHECK: cmpl %esi, 4(%rdi)
; CHECK: jge LBB4_2
; CHECK: movl $100, %eax
; CHECK: retq
; CHECK: [[BB1_imp_null_check_via_mem_comparision:LBB4_[0-9]+]]:
; CHECK: movl $42, %eax
; CHECK: retq
; CHECK: LBB4_2:
; CHECK: movl $200, %eax
; CHECK: retq
entry:
%c = icmp eq i32* %x, null
br i1 %c, label %is_null, label %not_null, !make.implicit !0
is_null:
ret i32 42
not_null:
%x.loc = getelementptr i32, i32* %x, i32 1
%t = load i32, i32* %x.loc
%m = icmp slt i32 %t, %val
br i1 %m, label %ret_100, label %ret_200
ret_100:
ret i32 100
ret_200:
ret i32 200
}
define i32 @imp_null_check_gep_load_with_use_dep(i32* %x, i32 %a) {
; CHECK-LABEL: imp_null_check_gep_load_with_use_dep:
; CHECK: [[BB0_imp_null_check_gep_load_with_use_dep:L[^:]+]]:
; CHECK: movl (%rdi), %eax
; CHECK: addl %edi, %esi
; CHECK: leal 4(%rax,%rsi), %eax
; CHECK: retq
; CHECK: [[BB1_imp_null_check_gep_load_with_use_dep:LBB5_[0-9]+]]:
; CHECK: movl $42, %eax
; CHECK: retq
entry:
%c = icmp eq i32* %x, null
br i1 %c, label %is_null, label %not_null, !make.implicit !0
is_null:
ret i32 42
not_null:
%x.loc = getelementptr i32, i32* %x, i32 1
%y = ptrtoint i32* %x.loc to i32
%b = add i32 %a, %y
%t = load i32, i32* %x
%z = add i32 %t, %b
ret i32 %z
}
define void @imp_null_check_store(i32* %x) {
; CHECK-LABEL: _imp_null_check_store:
; CHECK: [[BB0_imp_null_check_store:L[^:]+]]:
; CHECK: movl $1, (%rdi)
; CHECK: retq
; CHECK: [[BB1_imp_null_check_store:LBB6_[0-9]+]]:
; CHECK: retq
entry:
%c = icmp eq i32* %x, null
br i1 %c, label %is_null, label %not_null, !make.implicit !0
is_null:
ret void
not_null:
store i32 1, i32* %x
ret void
}
define i32 @imp_null_check_neg_gep_load(i32* %x) {
; CHECK-LABEL: _imp_null_check_neg_gep_load:
; CHECK: [[BB0_imp_null_check_neg_gep_load:L[^:]+]]:
; CHECK: movl -128(%rdi), %eax
; CHECK: retq
; CHECK: [[BB1_imp_null_check_neg_gep_load:LBB7_[0-9]+]]:
; CHECK: movl $42, %eax
; CHECK: retq
entry:
%c = icmp eq i32* %x, null
br i1 %c, label %is_null, label %not_null, !make.implicit !0
is_null:
ret i32 42
not_null:
%x.gep = getelementptr i32, i32* %x, i32 -32
%t = load i32, i32* %x.gep
ret i32 %t
}
!0 = !{}
; CHECK-LABEL: __LLVM_FaultMaps:
; Version:
; CHECK-NEXT: .byte 1
; Reserved x2
; CHECK-NEXT: .byte 0
; CHECK-NEXT: .short 0
; # functions:
; CHECK-NEXT: .long 8
; FunctionAddr:
; CHECK-NEXT: .quad _imp_null_check_add_result
; NumFaultingPCs
; CHECK-NEXT: .long 1
; Reserved:
; CHECK-NEXT: .long 0
; Fault[0].Type:
; CHECK-NEXT: .long 1
; Fault[0].FaultOffset:
; CHECK-NEXT: .long [[BB0_imp_null_check_add_result]]-_imp_null_check_add_result
; Fault[0].HandlerOffset:
; CHECK-NEXT: .long [[BB1_imp_null_check_add_result]]-_imp_null_check_add_result
; FunctionAddr:
; CHECK-NEXT: .quad _imp_null_check_gep_load
; NumFaultingPCs
; CHECK-NEXT: .long 1
; Reserved:
; CHECK-NEXT: .long 0
; Fault[0].Type:
; CHECK-NEXT: .long 1
; Fault[0].FaultOffset:
; CHECK-NEXT: .long [[BB0_imp_null_check_gep_load]]-_imp_null_check_gep_load
; Fault[0].HandlerOffset:
; CHECK-NEXT: .long [[BB1_imp_null_check_gep_load]]-_imp_null_check_gep_load
; FunctionAddr:
; CHECK-NEXT: .quad _imp_null_check_gep_load_with_use_dep
; NumFaultingPCs
; CHECK-NEXT: .long 1
; Reserved:
; CHECK-NEXT: .long 0
; Fault[0].Type:
; CHECK-NEXT: .long 1
; Fault[0].FaultOffset:
; CHECK-NEXT: .long [[BB0_imp_null_check_gep_load_with_use_dep]]-_imp_null_check_gep_load_with_use_dep
; Fault[0].HandlerOffset:
; CHECK-NEXT: .long [[BB1_imp_null_check_gep_load_with_use_dep]]-_imp_null_check_gep_load_with_use_dep
; FunctionAddr:
; CHECK-NEXT: .quad _imp_null_check_hoist_over_unrelated_load
; NumFaultingPCs
; CHECK-NEXT: .long 1
; Reserved:
; CHECK-NEXT: .long 0
; Fault[0].Type:
; CHECK-NEXT: .long 1
; Fault[0].FaultOffset:
; CHECK-NEXT: .long [[BB0_imp_null_check_hoist_over_unrelated_load]]-_imp_null_check_hoist_over_unrelated_load
; Fault[0].HandlerOffset:
; CHECK-NEXT: .long [[BB1_imp_null_check_hoist_over_unrelated_load]]-_imp_null_check_hoist_over_unrelated_load
; FunctionAddr:
; CHECK-NEXT: .quad _imp_null_check_load
; NumFaultingPCs
; CHECK-NEXT: .long 1
; Reserved:
; CHECK-NEXT: .long 0
; Fault[0].Type:
; CHECK-NEXT: .long 1
; Fault[0].FaultOffset:
; CHECK-NEXT: .long [[BB0_imp_null_check_load]]-_imp_null_check_load
; Fault[0].HandlerOffset:
; CHECK-NEXT: .long [[BB1_imp_null_check_load]]-_imp_null_check_load
; FunctionAddr:
; CHECK-NEXT: .quad _imp_null_check_neg_gep_load
; NumFaultingPCs
; CHECK-NEXT: .long 1
; Reserved:
; CHECK-NEXT: .long 0
; Fault[0].Type:
; CHECK-NEXT: .long 1
; Fault[0].FaultOffset:
; CHECK-NEXT: .long [[BB0_imp_null_check_neg_gep_load]]-_imp_null_check_neg_gep_load
; Fault[0].HandlerOffset:
; CHECK-NEXT: .long [[BB1_imp_null_check_neg_gep_load]]-_imp_null_check_neg_gep_load
; FunctionAddr:
; CHECK-NEXT: .quad _imp_null_check_store
; NumFaultingPCs
; CHECK-NEXT: .long 1
; Reserved:
; CHECK-NEXT: .long 0
; Fault[0].Type:
; CHECK-NEXT: .long 3
; Fault[0].FaultOffset:
; CHECK-NEXT: .long [[BB0_imp_null_check_store]]-_imp_null_check_store
; Fault[0].HandlerOffset:
; CHECK-NEXT: .long [[BB1_imp_null_check_store]]-_imp_null_check_store
; FunctionAddr:
; CHECK-NEXT: .quad _imp_null_check_via_mem_comparision
; NumFaultingPCs
; CHECK-NEXT: .long 1
; Reserved:
; CHECK-NEXT: .long 0
; Fault[0].Type:
; CHECK-NEXT: .long 1
; Fault[0].FaultOffset:
; CHECK-NEXT: .long [[BB0_imp_null_check_via_mem_comparision]]-_imp_null_check_via_mem_comparision
; Fault[0].HandlerOffset:
; CHECK-NEXT: .long [[BB1_imp_null_check_via_mem_comparision]]-_imp_null_check_via_mem_comparision
; OBJDUMP: FaultMap table:
; OBJDUMP-NEXT: Version: 0x1
; OBJDUMP-NEXT: NumFunctions: 8
; OBJDUMP-NEXT: FunctionAddress: 0x000000, NumFaultingPCs: 1
; OBJDUMP-NEXT: Fault kind: FaultingLoad, faulting PC offset: 0, handling PC offset: 5
; OBJDUMP-NEXT: FunctionAddress: 0x000000, NumFaultingPCs: 1
; OBJDUMP-NEXT: Fault kind: FaultingLoad, faulting PC offset: 0, handling PC offset: 7
; OBJDUMP-NEXT: FunctionAddress: 0x000000, NumFaultingPCs: 1
; OBJDUMP-NEXT: Fault kind: FaultingLoad, faulting PC offset: 0, handling PC offset: 9
; OBJDUMP-NEXT: FunctionAddress: 0x000000, NumFaultingPCs: 1
; OBJDUMP-NEXT: Fault kind: FaultingLoad, faulting PC offset: 0, handling PC offset: 7
; OBJDUMP-NEXT: FunctionAddress: 0x000000, NumFaultingPCs: 1
; OBJDUMP-NEXT: Fault kind: FaultingLoad, faulting PC offset: 0, handling PC offset: 3
; OBJDUMP-NEXT: FunctionAddress: 0x000000, NumFaultingPCs: 1
; OBJDUMP-NEXT: Fault kind: FaultingLoad, faulting PC offset: 0, handling PC offset: 4
; OBJDUMP-NEXT: FunctionAddress: 0x000000, NumFaultingPCs: 1
; OBJDUMP-NEXT: Fault kind: FaultingStore, faulting PC offset: 0, handling PC offset: 7
; OBJDUMP-NEXT: FunctionAddress: 0x000000, NumFaultingPCs: 1
; OBJDUMP-NEXT: Fault kind: FaultingLoad, faulting PC offset: 0, handling PC offset: 11