mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2025-10-30 16:17:05 +00:00
8f832fce3b
This was motivated by a bug which caused code like this to be
miscompiled:
declare void @take_ptr(i8*)
define void @test() {
%addr1.32 = alloca i8
%addr2.32 = alloca i32, i32 1028
call void @take_ptr(i8* %addr1)
ret void
}
This was emitting the following assembly to get the value of %addr1:
add r0, sp, #1020
add r0, r0, #8
However, "add r0, r0, #8" is not a valid Thumb1 instruction, and this
could not be assembled. The generated object file contained this,
resulting in r0 holding SP+8 rather tha SP+1028:
add r0, sp, #1020
add r0, sp, #8
This function looked like it could have caused miscompilations for
other combinations of registers and offsets (though I don't think it is
currently called with these), and the heuristic it used did not match
the emitted code in all cases.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222125 91177308-0d34-0410-b5e6-96231b3b80d8
144 lines
3.3 KiB
LLVM
144 lines
3.3 KiB
LLVM
; RUN: llc < %s -mtriple=thumbv6-apple-darwin | FileCheck %s
|
|
; RUN: llc < %s -mtriple=thumbv6-apple-darwin -regalloc=basic | FileCheck %s
|
|
; RUN: llc < %s -o %t -filetype=obj -mtriple=thumbv6-apple-darwin
|
|
; RUN: llvm-objdump -triple=thumbv6-apple-darwin -d %t | FileCheck %s
|
|
|
|
@__bar = external hidden global i8*
|
|
@__baz = external hidden global i8*
|
|
|
|
; rdar://8819685
|
|
define i8* @_foo() {
|
|
entry:
|
|
; CHECK-LABEL: foo:
|
|
|
|
%size = alloca i32, align 4
|
|
%0 = load i8** @__bar, align 4
|
|
%1 = icmp eq i8* %0, null
|
|
br i1 %1, label %bb1, label %bb3
|
|
; CHECK: bne
|
|
|
|
bb1:
|
|
store i32 1026, i32* %size, align 4
|
|
%2 = alloca [1026 x i8], align 1
|
|
; CHECK: mov [[R0:r[0-9]+]], sp
|
|
; CHECK: adds {{r[0-9]+}}, [[R0]], {{r[0-9]+}}
|
|
%3 = getelementptr inbounds [1026 x i8]* %2, i32 0, i32 0
|
|
%4 = call i32 @_called_func(i8* %3, i32* %size) nounwind
|
|
%5 = icmp eq i32 %4, 0
|
|
br i1 %5, label %bb2, label %bb3
|
|
|
|
bb2:
|
|
%6 = call i8* @strdup(i8* %3) nounwind
|
|
store i8* %6, i8** @__baz, align 4
|
|
br label %bb3
|
|
|
|
bb3:
|
|
%.0 = phi i8* [ %0, %entry ], [ %6, %bb2 ], [ %3, %bb1 ]
|
|
; CHECK: subs r4, #5
|
|
; CHECK-NEXT: mov sp, r4
|
|
; CHECK-NEXT: pop {r4, r5, r6, r7, pc}
|
|
ret i8* %.0
|
|
}
|
|
|
|
declare noalias i8* @strdup(i8* nocapture) nounwind
|
|
declare i32 @_called_func(i8*, i32*) nounwind
|
|
|
|
; Variable ending up at unaligned offset from sp (i.e. not a multiple of 4)
|
|
define void @test_local_var_addr() {
|
|
; CHECK-LABEL: test_local_var_addr:
|
|
|
|
%addr1 = alloca i8
|
|
%addr2 = alloca i8
|
|
|
|
; CHECK: mov r0, sp
|
|
; CHECK: adds r0, #{{[0-9]+}}
|
|
; CHECK: blx
|
|
call void @take_ptr(i8* %addr1)
|
|
|
|
; CHECK: mov r0, sp
|
|
; CHECK: adds r0, #{{[0-9]+}}
|
|
; CHECK: blx
|
|
call void @take_ptr(i8* %addr2)
|
|
|
|
ret void
|
|
}
|
|
|
|
; Simple variable ending up *at* sp.
|
|
define void @test_simple_var() {
|
|
; CHECK-LABEL: test_simple_var:
|
|
|
|
%addr32 = alloca i32
|
|
%addr8 = bitcast i32* %addr32 to i8*
|
|
|
|
; CHECK: mov r0, sp
|
|
; CHECK-NOT: adds r0
|
|
; CHECK: blx
|
|
call void @take_ptr(i8* %addr8)
|
|
ret void
|
|
}
|
|
|
|
; Simple variable ending up at aligned offset from sp.
|
|
define void @test_local_var_addr_aligned() {
|
|
; CHECK-LABEL: test_local_var_addr_aligned:
|
|
|
|
%addr1.32 = alloca i32
|
|
%addr1 = bitcast i32* %addr1.32 to i8*
|
|
%addr2.32 = alloca i32
|
|
%addr2 = bitcast i32* %addr2.32 to i8*
|
|
|
|
; CHECK: add r0, sp, #{{[0-9]+}}
|
|
; CHECK: blx
|
|
call void @take_ptr(i8* %addr1)
|
|
|
|
; CHECK: mov r0, sp
|
|
; CHECK-NOT: add r0
|
|
; CHECK: blx
|
|
call void @take_ptr(i8* %addr2)
|
|
|
|
ret void
|
|
}
|
|
|
|
; Simple variable ending up at aligned offset from sp.
|
|
define void @test_local_var_big_offset() {
|
|
; CHECK-LABEL: test_local_var_big_offset:
|
|
%addr1.32 = alloca i32, i32 257
|
|
%addr1 = bitcast i32* %addr1.32 to i8*
|
|
%addr2.32 = alloca i32, i32 257
|
|
|
|
; CHECK: add [[RTMP:r[0-9]+]], sp, #1020
|
|
; CHECK: adds [[RTMP]], #8
|
|
; CHECK: blx
|
|
call void @take_ptr(i8* %addr1)
|
|
|
|
ret void
|
|
}
|
|
|
|
; Max range addressable with tADDrSPi
|
|
define void @test_local_var_offset_1020() {
|
|
; CHECK-LABEL: test_local_var_offset_1020
|
|
%addr1 = alloca i8, i32 4
|
|
%addr2 = alloca i8, i32 1020
|
|
|
|
; CHECK: add r0, sp, #1020
|
|
; CHECK-NEXT: blx
|
|
call void @take_ptr(i8* %addr1)
|
|
|
|
ret void
|
|
}
|
|
|
|
; Max range addressable with tADDrSPi + tADDi8
|
|
define void @test_local_var_offset_1275() {
|
|
; CHECK-LABEL: test_local_var_offset_1275
|
|
%addr1 = alloca i8, i32 1
|
|
%addr2 = alloca i8, i32 1275
|
|
|
|
; CHECK: add r0, sp, #1020
|
|
; CHECK: adds r0, #255
|
|
; CHECK-NEXT: blx
|
|
call void @take_ptr(i8* %addr1)
|
|
|
|
ret void
|
|
}
|
|
|
|
declare void @take_ptr(i8*)
|