1
0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-23 11:13:28 +01:00
llvm-mirror/test/Transforms/InstCombine/wcslen-1.ll
Matthias Braun be57ef6b4f SimplifyLibCalls: Optimize wcslen
Refactor the strlen optimization code to work for both strlen and wcslen.

This especially helps with programs in the wild where people pass
L"string"s to const std::wstring& function parameters and the wstring
constructor gets inlined.

This also fixes a lingerind API problem/bug in getConstantStringInfo()
where zeroinitializers would always give you an empty string (without a
length) back regardless of the actual length of the initializer which
did not work well in the TrimAtNul==false causing the PR mentioned
below.

Note that the fixed getConstantStringInfo() needed fixes to SelectionDAG
memcpy lowering and may lead to some cases for out-of-bounds
zeroinitializer accesses not getting optimized anymore. So some code
with UB may produce out of bound memory reads now instead of just
producing zeros.

The refactoring "accidentally" fixes http://llvm.org/PR32124

Differential Revision: https://reviews.llvm.org/D32839

llvm-svn: 303461
2017-05-19 22:37:09 +00:00

192 lines
6.2 KiB
LLVM

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; Test that the wcslen library call simplifier works correctly.
;
; RUN: opt < %s -instcombine -S | FileCheck %s
target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
declare i64 @wcslen(i32*)
@hello = constant [6 x i32] [i32 104, i32 101, i32 108, i32 108, i32 111, i32 0]
@longer = constant [7 x i32] [i32 108, i32 111, i32 110, i32 103, i32 101, i32 114, i32 0]
@null = constant [1 x i32] zeroinitializer
@null_hello = constant [7 x i32] [i32 0, i32 104, i32 101, i32 108, i32 108, i32 111, i32 0]
@nullstring = constant i32 0
@a = common global [32 x i32] zeroinitializer, align 1
@null_hello_mid = constant [13 x i32] [i32 104, i32 101, i32 108, i32 108, i32 111, i32 32, i32 119, i32 111, i32 114, i32 0, i32 108, i32 100, i32 0]
define i64 @test_simplify1() {
; CHECK-LABEL: @test_simplify1(
; CHECK-NEXT: ret i64 5
;
%hello_p = getelementptr [6 x i32], [6 x i32]* @hello, i64 0, i64 0
%hello_l = call i64 @wcslen(i32* %hello_p)
ret i64 %hello_l
}
define i64 @test_simplify2() {
; CHECK-LABEL: @test_simplify2(
; CHECK-NEXT: ret i64 0
;
%null_p = getelementptr [1 x i32], [1 x i32]* @null, i64 0, i64 0
%null_l = call i64 @wcslen(i32* %null_p)
ret i64 %null_l
}
define i64 @test_simplify3() {
; CHECK-LABEL: @test_simplify3(
; CHECK-NEXT: ret i64 0
;
%null_hello_p = getelementptr [7 x i32], [7 x i32]* @null_hello, i64 0, i64 0
%null_hello_l = call i64 @wcslen(i32* %null_hello_p)
ret i64 %null_hello_l
}
define i64 @test_simplify4() {
; CHECK-LABEL: @test_simplify4(
; CHECK-NEXT: ret i64 0
;
%len = tail call i64 @wcslen(i32* @nullstring) nounwind
ret i64 %len
}
; Check wcslen(x) == 0 --> *x == 0.
define i1 @test_simplify5() {
; CHECK-LABEL: @test_simplify5(
; CHECK-NEXT: ret i1 false
;
%hello_p = getelementptr [6 x i32], [6 x i32]* @hello, i64 0, i64 0
%hello_l = call i64 @wcslen(i32* %hello_p)
%eq_hello = icmp eq i64 %hello_l, 0
ret i1 %eq_hello
}
define i1 @test_simplify6(i32* %str_p) {
; CHECK-LABEL: @test_simplify6(
; CHECK-NEXT: [[STRLENFIRST:%.*]] = load i32, i32* [[STR_P:%.*]], align 4
; CHECK-NEXT: [[EQ_NULL:%.*]] = icmp eq i32 [[STRLENFIRST]], 0
; CHECK-NEXT: ret i1 [[EQ_NULL]]
;
%str_l = call i64 @wcslen(i32* %str_p)
%eq_null = icmp eq i64 %str_l, 0
ret i1 %eq_null
}
; Check wcslen(x) != 0 --> *x != 0.
define i1 @test_simplify7() {
; CHECK-LABEL: @test_simplify7(
; CHECK-NEXT: ret i1 true
;
%hello_p = getelementptr [6 x i32], [6 x i32]* @hello, i64 0, i64 0
%hello_l = call i64 @wcslen(i32* %hello_p)
%ne_hello = icmp ne i64 %hello_l, 0
ret i1 %ne_hello
}
define i1 @test_simplify8(i32* %str_p) {
; CHECK-LABEL: @test_simplify8(
; CHECK-NEXT: [[STRLENFIRST:%.*]] = load i32, i32* [[STR_P:%.*]], align 4
; CHECK-NEXT: [[NE_NULL:%.*]] = icmp ne i32 [[STRLENFIRST]], 0
; CHECK-NEXT: ret i1 [[NE_NULL]]
;
%str_l = call i64 @wcslen(i32* %str_p)
%ne_null = icmp ne i64 %str_l, 0
ret i1 %ne_null
}
define i64 @test_simplify9(i1 %x) {
; CHECK-LABEL: @test_simplify9(
; CHECK-NEXT: [[TMP1:%.*]] = select i1 [[X:%.*]], i64 5, i64 6
; CHECK-NEXT: ret i64 [[TMP1]]
;
%hello = getelementptr [6 x i32], [6 x i32]* @hello, i64 0, i64 0
%longer = getelementptr [7 x i32], [7 x i32]* @longer, i64 0, i64 0
%s = select i1 %x, i32* %hello, i32* %longer
%l = call i64 @wcslen(i32* %s)
ret i64 %l
}
; Check the case that should be simplified to a sub instruction.
; wcslen(@hello + x) --> 5 - x
define i64 @test_simplify10(i32 %x) {
; CHECK-LABEL: @test_simplify10(
; CHECK-NEXT: [[TMP1:%.*]] = sext i32 [[X:%.*]] to i64
; CHECK-NEXT: [[TMP2:%.*]] = sub nsw i64 5, [[TMP1]]
; CHECK-NEXT: ret i64 [[TMP2]]
;
%hello_p = getelementptr inbounds [6 x i32], [6 x i32]* @hello, i32 0, i32 %x
%hello_l = call i64 @wcslen(i32* %hello_p)
ret i64 %hello_l
}
; wcslen(@null_hello_mid + (x & 7)) --> 9 - (x & 7)
define i64 @test_simplify11(i32 %x) {
; CHECK-LABEL: @test_simplify11(
; CHECK-NEXT: [[AND:%.*]] = and i32 [[X:%.*]], 7
; CHECK-NEXT: [[TMP1:%.*]] = zext i32 [[AND]] to i64
; CHECK-NEXT: [[TMP2:%.*]] = sub nsw i64 9, [[TMP1]]
; CHECK-NEXT: ret i64 [[TMP2]]
;
%and = and i32 %x, 7
%hello_p = getelementptr inbounds [13 x i32], [13 x i32]* @null_hello_mid, i32 0, i32 %and
%hello_l = call i64 @wcslen(i32* %hello_p)
ret i64 %hello_l
}
; Check cases that shouldn't be simplified.
define i64 @test_no_simplify1() {
; CHECK-LABEL: @test_no_simplify1(
; CHECK-NEXT: [[A_L:%.*]] = call i64 @wcslen(i32* getelementptr inbounds ([32 x i32], [32 x i32]* @a, i64 0, i64 0))
; CHECK-NEXT: ret i64 [[A_L]]
;
%a_p = getelementptr [32 x i32], [32 x i32]* @a, i64 0, i64 0
%a_l = call i64 @wcslen(i32* %a_p)
ret i64 %a_l
}
; wcslen(@null_hello + x) should not be simplified to a sub instruction.
define i64 @test_no_simplify2(i32 %x) {
; CHECK-LABEL: @test_no_simplify2(
; CHECK-NEXT: [[TMP1:%.*]] = sext i32 [[X:%.*]] to i64
; CHECK-NEXT: [[HELLO_P:%.*]] = getelementptr inbounds [7 x i32], [7 x i32]* @null_hello, i64 0, i64 [[TMP1]]
; CHECK-NEXT: [[HELLO_L:%.*]] = call i64 @wcslen(i32* [[HELLO_P]])
; CHECK-NEXT: ret i64 [[HELLO_L]]
;
%hello_p = getelementptr inbounds [7 x i32], [7 x i32]* @null_hello, i32 0, i32 %x
%hello_l = call i64 @wcslen(i32* %hello_p)
ret i64 %hello_l
}
; wcslen(@null_hello_mid + (x & 15)) should not be simplified to a sub instruction.
define i64 @test_no_simplify3(i32 %x) {
; CHECK-LABEL: @test_no_simplify3(
; CHECK-NEXT: [[AND:%.*]] = and i32 [[X:%.*]], 15
; CHECK-NEXT: [[TMP1:%.*]] = zext i32 [[AND]] to i64
; CHECK-NEXT: [[HELLO_P:%.*]] = getelementptr inbounds [13 x i32], [13 x i32]* @null_hello_mid, i64 0, i64 [[TMP1]]
; CHECK-NEXT: [[HELLO_L:%.*]] = call i64 @wcslen(i32* [[HELLO_P]])
; CHECK-NEXT: ret i64 [[HELLO_L]]
;
%and = and i32 %x, 15
%hello_p = getelementptr inbounds [13 x i32], [13 x i32]* @null_hello_mid, i32 0, i32 %and
%hello_l = call i64 @wcslen(i32* %hello_p)
ret i64 %hello_l
}
@str16 = constant [1 x i16] [i16 0]
define i64 @test_no_simplify4() {
; CHECK-LABEL: @test_no_simplify4(
; CHECK-NEXT: [[L:%.*]] = call i64 @wcslen(i32* bitcast ([1 x i16]* @str16 to i32*))
; CHECK-NEXT: ret i64 [[L]]
;
%l = call i64 @wcslen(i32* bitcast ([1 x i16]* @str16 to i32*))
ret i64 %l
}