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llvm-project/llvm/test/CodeGen/PowerPC/sjlj.ll

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Implement builtin_{setjmp/longjmp} on PPC This implements SJLJ lowering on PPC, making the Clang functions __builtin_{setjmp/longjmp} functional on PPC platforms. The implementation strategy is similar to that on X86, with the exception that a branch-and-link variant is used to get the right jump address. Credit goes to Bill Schmidt for suggesting the use of the unconditional bcl form (instead of the regular bl instruction) to limit return-address-cache pollution. Benchmarking the speed at -O3 of: static jmp_buf env_sigill; void foo() { __builtin_longjmp(env_sigill,1); } main() { ... for (int i = 0; i < c; ++i) { if (__builtin_setjmp(env_sigill)) { goto done; } else { foo(); } done:; } ... } vs. the same code using the libc setjmp/longjmp functions on a P7 shows that this builtin implementation is ~4x faster with Altivec enabled and ~7.25x faster with Altivec disabled. This comparison is somewhat unfair because the libc version must also save/restore the VSX registers which we don't yet support. llvm-svn: 177666
2013-03-22 05:37:52 +08:00
; RUN: llc < %s -mtriple=powerpc64-unknown-linux-gnu -mcpu=pwr7 | FileCheck %s
; RUN: llc < %s -mtriple=powerpc64-unknown-linux-gnu -mcpu=a2 | FileCheck -check-prefix=CHECK-NOAV %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-f128:128:128-v128:128:128-n32:64"
target triple = "powerpc64-unknown-linux-gnu"
%struct.__jmp_buf_tag = type { [64 x i64], i32, %struct.__sigset_t, [8 x i8] }
%struct.__sigset_t = type { [16 x i64] }
@env_sigill = internal global [1 x %struct.__jmp_buf_tag] zeroinitializer, align 16
define void @foo() #0 {
entry:
call void @llvm.eh.sjlj.longjmp(i8* bitcast ([1 x %struct.__jmp_buf_tag]* @env_sigill to i8*))
unreachable
; CHECK: @foo
; CHECK: addis [[REG:[0-9]+]], 2, env_sigill@toc@ha
; CHECK: addi [[REG]], [[REG]], env_sigill@toc@l
; CHECK: ld 31, 0([[REG]])
; CHECK: ld [[REG2:[0-9]+]], 8([[REG]])
; CHECK: ld 1, 16([[REG]])
; CHECK: mtctr [[REG2]]
; CHECK: ld 2, 24([[REG]])
; CHECK: bctr
return: ; No predecessors!
ret void
}
declare void @llvm.eh.sjlj.longjmp(i8*) #1
define signext i32 @main() #0 {
entry:
%retval = alloca i32, align 4
store i32 0, i32* %retval
%0 = call i8* @llvm.frameaddress(i32 0)
store i8* %0, i8** bitcast ([1 x %struct.__jmp_buf_tag]* @env_sigill to i8**)
%1 = call i8* @llvm.stacksave()
store i8* %1, i8** getelementptr (i8** bitcast ([1 x %struct.__jmp_buf_tag]* @env_sigill to i8**), i32 2)
%2 = call i32 @llvm.eh.sjlj.setjmp(i8* bitcast ([1 x %struct.__jmp_buf_tag]* @env_sigill to i8*))
%tobool = icmp ne i32 %2, 0
br i1 %tobool, label %if.then, label %if.else
if.then: ; preds = %entry
store i32 1, i32* %retval
br label %return
if.else: ; preds = %entry
call void @foo()
br label %if.end
if.end: ; preds = %if.else
store i32 0, i32* %retval
br label %return
return: ; preds = %if.end, %if.then
%3 = load i32* %retval
ret i32 %3
Don't spill PPC VRSAVE on non-Darwin (even in SjLj) As Bill Schmidt pointed out to me, only on Darwin do we need to spill/restore VRSAVE in the SjLj code. For non-Darwin, don't spill/restore VRSAVE (and I've added some asserts to make sure that we're not). As it turns out, we're not currently handling the Darwin case correctly (I've added a FIXME in the test case). I've tried adding various implied register definitions/uses to force the spill without success, so I'll need to address this later. llvm-svn: 178096
2013-03-27 08:02:20 +08:00
; FIXME: We should be saving VRSAVE on Darwin, but we're not!
Implement builtin_{setjmp/longjmp} on PPC This implements SJLJ lowering on PPC, making the Clang functions __builtin_{setjmp/longjmp} functional on PPC platforms. The implementation strategy is similar to that on X86, with the exception that a branch-and-link variant is used to get the right jump address. Credit goes to Bill Schmidt for suggesting the use of the unconditional bcl form (instead of the regular bl instruction) to limit return-address-cache pollution. Benchmarking the speed at -O3 of: static jmp_buf env_sigill; void foo() { __builtin_longjmp(env_sigill,1); } main() { ... for (int i = 0; i < c; ++i) { if (__builtin_setjmp(env_sigill)) { goto done; } else { foo(); } done:; } ... } vs. the same code using the libc setjmp/longjmp functions on a P7 shows that this builtin implementation is ~4x faster with Altivec enabled and ~7.25x faster with Altivec disabled. This comparison is somewhat unfair because the libc version must also save/restore the VSX registers which we don't yet support. llvm-svn: 177666
2013-03-22 05:37:52 +08:00
; CHECK: @main
; CHECK: std
Don't spill PPC VRSAVE on non-Darwin (even in SjLj) As Bill Schmidt pointed out to me, only on Darwin do we need to spill/restore VRSAVE in the SjLj code. For non-Darwin, don't spill/restore VRSAVE (and I've added some asserts to make sure that we're not). As it turns out, we're not currently handling the Darwin case correctly (I've added a FIXME in the test case). I've tried adding various implied register definitions/uses to force the spill without success, so I'll need to address this later. llvm-svn: 178096
2013-03-27 08:02:20 +08:00
; Make sure that we're not saving VRSAVE on non-Darwin:
; CHECK-NOT: mfspr
Implement builtin_{setjmp/longjmp} on PPC This implements SJLJ lowering on PPC, making the Clang functions __builtin_{setjmp/longjmp} functional on PPC platforms. The implementation strategy is similar to that on X86, with the exception that a branch-and-link variant is used to get the right jump address. Credit goes to Bill Schmidt for suggesting the use of the unconditional bcl form (instead of the regular bl instruction) to limit return-address-cache pollution. Benchmarking the speed at -O3 of: static jmp_buf env_sigill; void foo() { __builtin_longjmp(env_sigill,1); } main() { ... for (int i = 0; i < c; ++i) { if (__builtin_setjmp(env_sigill)) { goto done; } else { foo(); } done:; } ... } vs. the same code using the libc setjmp/longjmp functions on a P7 shows that this builtin implementation is ~4x faster with Altivec enabled and ~7.25x faster with Altivec disabled. This comparison is somewhat unfair because the libc version must also save/restore the VSX registers which we don't yet support. llvm-svn: 177666
2013-03-22 05:37:52 +08:00
; CHECK: stfd
; CHECK: stvx
; CHECK: addis [[REG:[0-9]+]], 2, env_sigill@toc@ha
; CHECK: std 31, env_sigill@toc@l([[REG]])
; CHECK: addi [[REG]], [[REG]], env_sigill@toc@l
; CHECK: std [[REG]], [[OFF:[0-9]+]](31) # 8-byte Folded Spill
; CHECK: std 1, 16([[REG]])
; CHECK: std 2, 24([[REG]])
; CHECK: bcl 20, 31, .LBB1_1
; CHECK: li 3, 1
; CHECK: #EH_SjLj_Setup .LBB1_1
; CHECK: b .LBB1_2
; CHECK: .LBB1_1:
; CHECK: mflr [[REGL:[0-9]+]]
; CHECK: ld [[REG2:[0-9]+]], [[OFF]](31) # 8-byte Folded Reload
; CHECK: std [[REGL]], 8([[REG2]])
; CHECK: li 3, 0
; CHECK: .LBB1_2:
; CHECK: lfd
; CHECK: lvx
; CHECK: ld
; CHECK: blr
; CHECK-NOAV: @main
; CHECK-NOAV-NOT: stvx
; CHECK-NOAV: bcl
; CHECK-NOAV: mflr
; CHECK-NOAV: bl foo
; CHECK-NOAV-NOT: lvx
; CHECK-NOAV: blr
}
declare i8* @llvm.frameaddress(i32) #2
declare i8* @llvm.stacksave() #3
declare i32 @llvm.eh.sjlj.setjmp(i8*) #3
attributes #0 = { nounwind "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-frame-pointer-elim-non-leaf"="true" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "unsafe-fp-math"="false" "use-soft-float"="false" }
attributes #1 = { noreturn nounwind }
attributes #2 = { nounwind readnone }
attributes #3 = { nounwind }