llvm-6502/test/CodeGen/PowerPC/ppc64-calls.ll
Hal Finkel c9e5247ea7 [PowerPC] Ensure that the TOC reload directly follows bctrl on PPC64
On non-Darwin PPC64, the TOC reload needs to come directly after the bctrl
instruction (for indirect calls) because the 'bctrl/ld 2, 40(1)' instruction
sequence is interpreted by the unwinding code in libgcc. To make sure these
occur as a pair, as with other pairings interpreted by the linker, fuse the two
instructions into one instruction (for code generation only).

In the future, we might wish to do this by emitting CFI directives instead,
but this solution is simpler, and mirrors what GCC does. Additional discussion
on this point is contained in the PR.

Fixes PR22015.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224788 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-23 22:29:40 +00:00

87 lines
2.2 KiB
LLVM

; RUN: llc < %s -march=ppc64 -mcpu=pwr7 | FileCheck %s
target datalayout = "E-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v128:128:128-n32:64"
target triple = "powerpc64-unknown-linux-gnu"
define void @foo() nounwind readnone noinline {
ret void
}
define weak void @foo_weak() nounwind {
ret void
}
; Calls to local function does not require the TOC restore 'nop'
define void @test_direct() nounwind readnone {
; CHECK-LABEL: test_direct:
tail call void @foo() nounwind
; CHECK: bl foo
; CHECK-NOT: nop
ret void
}
; Calls to weak function requires a TOC restore 'nop' because they
; may be overridden in a different module.
define void @test_weak() nounwind readnone {
; CHECK-LABEL: test_weak:
tail call void @foo_weak() nounwind
; CHECK: bl foo
; CHECK-NEXT: nop
ret void
}
; Indirect calls requires a full stub creation
define void @test_indirect(void ()* nocapture %fp) nounwind {
; CHECK-LABEL: test_indirect:
tail call void %fp() nounwind
; CHECK: ld [[FP:[0-9]+]], 0(3)
; CHECK: ld 11, 16(3)
; CHECK: ld 2, 8(3)
; CHECK-NEXT: mtctr [[FP]]
; CHECK-NEXT: bctrl
; CHECK-NEXT: ld 2, 40(1)
ret void
}
; Absolute values must use the regular indirect call sequence
; The main purpose of this test is to ensure that BLA is not
; used on 64-bit SVR4 (as e.g. on Darwin).
define void @test_abs() nounwind {
; CHECK-LABEL: test_abs:
tail call void inttoptr (i64 1024 to void ()*)() nounwind
; CHECK: ld [[FP:[0-9]+]], 1024(0)
; CHECK: ld 11, 1040(0)
; CHECK: ld 2, 1032(0)
; CHECK-NEXT: mtctr [[FP]]
; CHECK-NEXT: bctrl
; CHECK-NEXT: ld 2, 40(1)
ret void
}
declare double @sin(double) nounwind
; External functions call should also have a 'nop'
define double @test_external(double %x) nounwind {
; CHECK-LABEL: test_external:
%call = tail call double @sin(double %x) nounwind
; CHECK: bl sin
; CHECK-NEXT: nop
ret double %call
}
; The 'ld 2, 40(1)' really must always come directly after the bctrl to make
; the unwinding code in libgcc happy.
@g = external global void ()*
declare void @h(i64)
define void @test_indir_toc_reload(i64 %x) {
%1 = load void ()** @g
call void %1()
call void @h(i64 %x)
ret void
; CHECK-LABEL: @test_indir_toc_reload
; CHECK: bctrl
; CHECK-NEXT: ld 2, 40(1)
; CHECK: blr
}