MCSE-caller-preserved-reg.ll
2.39 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc -relocation-model=pic -verify-machineinstrs -mtriple=powerpc64le-unknown-linux-gnu < %s | FileCheck %s
; The instructions addis,addi, bl are used to calculate the address of TLS
; thread local variables. These TLS access code sequences are generated
; repeatedly every time the thread local variable is accessed. By communicating
; to Machine CSE that X2 is guaranteed to have the same value within the same
; function call (so called Caller Preserved Physical Register), the redudant
; TLS access code sequences are cleaned up.
%"struct.CC::TT" = type { i64, i32 }
%class.CC = type { %struct.SS }
%struct.SS = type { void ()* }
@_ZN2CC2ccE = external thread_local global %"struct.CC::TT", align 8
define noalias i8* @_ZN2CC3funEv(%class.CC* %this) nounwind {
; CHECK-LABEL: _ZN2CC3funEv:
; CHECK: # %bb.0: # %entry
; CHECK-NEXT: mflr 0
; CHECK-NEXT: std 30, -16(1) # 8-byte Folded Spill
; CHECK-NEXT: std 0, 16(1)
; CHECK-NEXT: stdu 1, -48(1)
; CHECK-NEXT: std 2, 24(1)
; CHECK-NEXT: mr 30, 3
; CHECK-NEXT: ld 12, 0(3)
; CHECK-NEXT: mtctr 12
; CHECK-NEXT: bctrl
; CHECK-NEXT: ld 2, 24(1)
; CHECK-NEXT: addis 3, 2, _ZN2CC2ccE@got@tlsgd@ha
; CHECK-NEXT: addi 3, 3, _ZN2CC2ccE@got@tlsgd@l
; CHECK-NEXT: bl __tls_get_addr(_ZN2CC2ccE@tlsgd)
; CHECK-NEXT: nop
; CHECK-NEXT: ld 4, 0(3)
; CHECK-NEXT: cmpldi 4, 0
; CHECK-NEXT: beq 0, .LBB0_2
; CHECK-NEXT: # %bb.1: # %if.then
; CHECK-NEXT: addi 4, 3, 8
; CHECK-NEXT: mr 3, 30
; CHECK-NEXT: bl _ZN2CC3barEPi
; CHECK-NEXT: nop
; CHECK-NEXT: .LBB0_2: # %if.end
; CHECK-NEXT: li 3, 0
; CHECK-NEXT: addi 1, 1, 48
; CHECK-NEXT: ld 0, 16(1)
; CHECK-NEXT: ld 30, -16(1) # 8-byte Folded Reload
; CHECK-NEXT: mtlr 0
; CHECK-NEXT: blr
entry:
%foo = getelementptr inbounds %class.CC, %class.CC* %this, i64 0, i32 0, i32 0
%0 = load void ()*, void ()** %foo, align 8
tail call void %0()
%1 = load i64, i64* getelementptr inbounds (%"struct.CC::TT", %"struct.CC::TT"* @_ZN2CC2ccE, i64 0, i32 0)
%tobool = icmp eq i64 %1, 0
br i1 %tobool, label %if.end, label %if.then
if.then:
tail call void @_ZN2CC3barEPi(%class.CC* nonnull %this, i32* getelementptr inbounds (%"struct.CC::TT", %"struct.CC::TT"* @_ZN2CC2ccE, i64 0, i32 1))
br label %if.end
if.end:
ret i8* null
}
declare void @_ZN2CC3barEPi(%class.CC*, i32*)