llvm/test/CodeGen/X86/setjmp-spills.ll
Mark Seaborn dfa550a176 Fix llc to not reuse spill slots in functions that invoke setjmp()
We need to ensure that StackSlotColoring.cpp does not reuse stack
spill slots in functions that call "returns_twice" functions such as
setjmp(), otherwise this can lead to miscompiled code, because a stack
slot would be clobbered when it's still live.

This was already handled correctly for functions that call setjmp()
(though this wasn't covered by a test), but not for functions that
invoke setjmp().

We fix this by changing callsFunctionThatReturnsTwice() to check for
invoke instructions.

This fixes PR18244.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199180 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-14 04:20:01 +00:00

142 lines
3.9 KiB
LLVM

; RUN: llc < %s -mtriple=i386-linux | FileCheck %s -check-prefix=X86-32
; RUN: llc < %s -mtriple=x86_64-linux | FileCheck %s -check-prefix=X86-64
declare i32 @get_val()
declare void @use_val(i32)
declare i1 @setjmp()
declare void @longjmp()
declare void @personality()
; Test that llc avoids reusing spill slots in functions that call
; setjmp(), whether they use "call" or "invoke" for calling setjmp()
; (PR18244).
define void @setjmp_caller() {
; X86-32-LABEL: setjmp_caller:
; X86-64-LABEL: setjmp_caller:
; This code keeps enough variables live across the setjmp() call that
; they don't all fit in registers and the compiler will allocate a
; spill slot.
%a1 = call i32 @get_val()
%a2 = call i32 @get_val()
%a3 = call i32 @get_val()
%a4 = call i32 @get_val()
%a5 = call i32 @get_val()
%a6 = call i32 @get_val()
%a7 = call i32 @get_val()
%a8 = call i32 @get_val()
; X86-32: movl %eax, [[SPILL_SLOT:[0-9]+]](%esp)
; X86-32: calll get_val
; X86-64: movl %eax, [[SPILL_SLOT:[0-9]+]](%rsp)
; X86-64: callq get_val
%setjmp_result = call i1 @setjmp() returns_twice
br i1 %setjmp_result, label %second, label %first
; X86-32: calll setjmp
; X86-64: callq setjmp
; Again, keep enough variables live that they need spill slots. Since
; this function calls a returns_twice function (setjmp()), the
; compiler should not reuse the spill slots. longjmp() can return to
; where the first spill slots were still live.
first:
%b1 = call i32 @get_val()
%b2 = call i32 @get_val()
%b3 = call i32 @get_val()
%b4 = call i32 @get_val()
%b5 = call i32 @get_val()
%b6 = call i32 @get_val()
%b7 = call i32 @get_val()
%b8 = call i32 @get_val()
call void @use_val(i32 %b1)
call void @use_val(i32 %b2)
call void @use_val(i32 %b3)
call void @use_val(i32 %b4)
call void @use_val(i32 %b5)
call void @use_val(i32 %b6)
call void @use_val(i32 %b7)
call void @use_val(i32 %b8)
call void @longjmp()
unreachable
; X86-32-NOT: movl {{.*}}, [[SPILL_SLOT]](%esp)
; X86-64-NOT: movl {{.*}}, [[SPILL_SLOT]](%rsp)
second:
call void @use_val(i32 %a1)
call void @use_val(i32 %a2)
call void @use_val(i32 %a3)
call void @use_val(i32 %a4)
call void @use_val(i32 %a5)
call void @use_val(i32 %a6)
call void @use_val(i32 %a7)
call void @use_val(i32 %a8)
ret void
}
; This is the same as above, but using "invoke" rather than "call" to
; call setjmp().
define void @setjmp_invoker() {
; X86-32-LABEL: setjmp_invoker:
; X86-64-LABEL: setjmp_invoker:
%a1 = call i32 @get_val()
%a2 = call i32 @get_val()
%a3 = call i32 @get_val()
%a4 = call i32 @get_val()
%a5 = call i32 @get_val()
%a6 = call i32 @get_val()
%a7 = call i32 @get_val()
%a8 = call i32 @get_val()
; X86-32: movl %eax, [[SPILL_SLOT:[0-9]+]](%esp)
; X86-32: calll get_val
; X86-64: movl %eax, [[SPILL_SLOT:[0-9]+]](%rsp)
; X86-64: callq get_val
%setjmp_result = invoke i1 @setjmp() returns_twice
to label %cont unwind label %lpad
; X86-32: calll setjmp
; X86-64: callq setjmp
cont:
br i1 %setjmp_result, label %second, label %first
lpad:
%lp = landingpad { i8*, i32 } personality void ()* @personality cleanup
unreachable
first:
%b1 = call i32 @get_val()
%b2 = call i32 @get_val()
%b3 = call i32 @get_val()
%b4 = call i32 @get_val()
%b5 = call i32 @get_val()
%b6 = call i32 @get_val()
%b7 = call i32 @get_val()
%b8 = call i32 @get_val()
call void @use_val(i32 %b1)
call void @use_val(i32 %b2)
call void @use_val(i32 %b3)
call void @use_val(i32 %b4)
call void @use_val(i32 %b5)
call void @use_val(i32 %b6)
call void @use_val(i32 %b7)
call void @use_val(i32 %b8)
call void @longjmp()
unreachable
; X86-32-NOT: movl {{.*}}, [[SPILL_SLOT]](%esp)
; X86-64-NOT: movl {{.*}}, [[SPILL_SLOT]](%rsp)
second:
call void @use_val(i32 %a1)
call void @use_val(i32 %a2)
call void @use_val(i32 %a3)
call void @use_val(i32 %a4)
call void @use_val(i32 %a5)
call void @use_val(i32 %a6)
call void @use_val(i32 %a7)
call void @use_val(i32 %a8)
ret void
}