7adb2fdbba
This reverts r317579, originally committed as r317100.
There is a design issue with marking CFI instructions duplicatable. Not
all targets support the CFIInstrInserter pass, and targets like Darwin
can't cope with duplicated prologue setup CFI instructions. The compact
unwind info emission fails.
When the following code is compiled for arm64 on Mac at -O3, the CFI
instructions end up getting tail duplicated, which causes compact unwind
info emission to fail:
int a, c, d, e, f, g, h, i, j, k, l, m;
void n(int o, int *b) {
if (g)
f = 0;
for (; f < o; f++) {
m = a;
if (l > j * k > i)
j = i = k = d;
h = b[c] - e;
}
}
We get assembly that looks like this:
; BB#1: ; %if.then
Lloh3:
adrp x9, _f@GOTPAGE
Lloh4:
ldr x9, [x9, _f@GOTPAGEOFF]
mov w8, wzr
Lloh5:
str wzr, [x9]
stp x20, x19, [sp, #-16]! ; 8-byte Folded Spill
.cfi_def_cfa_offset 16
.cfi_offset w19, -8
.cfi_offset w20, -16
cmp w8, w0
b.lt LBB0_3
b LBB0_7
LBB0_2: ; %entry.if.end_crit_edge
Lloh6:
adrp x8, _f@GOTPAGE
Lloh7:
ldr x8, [x8, _f@GOTPAGEOFF]
Lloh8:
ldr w8, [x8]
stp x20, x19, [sp, #-16]! ; 8-byte Folded Spill
.cfi_def_cfa_offset 16
.cfi_offset w19, -8
.cfi_offset w20, -16
cmp w8, w0
b.ge LBB0_7
LBB0_3: ; %for.body.lr.ph
Note the multiple .cfi_def* directives. Compact unwind info emission
can't handle that.
llvm-svn: 317726
45 lines
1.6 KiB
LLVM
45 lines
1.6 KiB
LLVM
; RUN: llc < %s -mtriple=i686-pc-linux -filetype=obj | llvm-readobj -s -sr -sd | FileCheck %s -check-prefix=LINUX
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; RUN: llc < %s -mtriple=i686-darwin-macosx10.7 -filetype=obj | llvm-readobj -sections | FileCheck -check-prefix=DARWIN %s
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; On darwin, check that we manage to generate the compact unwind section
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; DARWIN: Name: __compact_unwind
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; DARWIN: Segment: __LD
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; LINUX: Name: .eh_frame
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; LINUX-NEXT: Type: SHT_PROGBITS (0x1)
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; LINUX-NEXT: Flags [ (0x2)
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; LINUX-NEXT: SHF_ALLOC (0x2)
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; LINUX-NEXT: ]
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; LINUX-NEXT: Address: 0x0
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; LINUX-NEXT: Offset: 0x68
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; LINUX-NEXT: Size: 64
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; LINUX-NEXT: Link: 0
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; LINUX-NEXT: Info: 0
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; LINUX-NEXT: AddressAlignment: 4
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; LINUX-NEXT: EntrySize: 0
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; LINUX-NEXT: Relocations [
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; LINUX-NEXT: ]
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; LINUX-NEXT: SectionData (
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; LINUX-NEXT: 0000: 1C000000 00000000 017A504C 5200017C |.........zPLR..||
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; LINUX-NEXT: 0010: 08070000 00000000 1B0C0404 88010000 |................|
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; LINUX-NEXT: 0020: 1C000000 24000000 00000000 1D000000 |....$...........|
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; LINUX-NEXT: 0030: 04000000 00410E08 8502420D 05432E10 |.....A....B..C..|
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; LINUX-NEXT: )
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declare i32 @__gxx_personality_v0(...)
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declare void @good(i32 %a, i32 %b, i32 %c, i32 %d)
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define void @test() #0 personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) {
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entry:
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invoke void @good(i32 1, i32 2, i32 3, i32 4)
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to label %continue unwind label %cleanup
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continue:
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ret void
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cleanup:
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landingpad { i8*, i32 }
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cleanup
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ret void
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}
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attributes #0 = { optsize "no-frame-pointer-elim"="true" }
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