From 40f76d583030084c557354ec4905dab45cb5cefe Mon Sep 17 00:00:00 2001 From: Hal Finkel Date: Wed, 17 Jul 2013 05:35:44 +0000 Subject: [PATCH] PPC: Add CTR-register clobber to builtin setjmp Because the builtin longjmp implementation uses a CTR-based indirect jump, when the control flow arrives at the builtin setjmp call, the CTR register has necessarily been clobbered. Correspondingly, this adds CTR to the list of implicit definitions of the builtin setjmp pseudo instruction. We don't need to add CTR to the implicit definitions of builtin longjmp because, even though it does clobber the CTR register, the control flow cannot return to inside the loop unless there is also a builtin setjmp call. llvm-svn: 186488 --- llvm/lib/Target/PowerPC/PPCCTRLoops.cpp | 7 +++++ llvm/lib/Target/PowerPC/PPCInstr64Bit.td | 1 + llvm/lib/Target/PowerPC/PPCInstrInfo.td | 1 + llvm/test/CodeGen/PowerPC/sj-ctr-loop.ll | 50 ++++++++++++++++++++++++++++++++ 4 files changed, 59 insertions(+) create mode 100644 llvm/test/CodeGen/PowerPC/sj-ctr-loop.ll diff --git a/llvm/lib/Target/PowerPC/PPCCTRLoops.cpp b/llvm/lib/Target/PowerPC/PPCCTRLoops.cpp index 30181a0..4e30c537 100644 --- a/llvm/lib/Target/PowerPC/PPCCTRLoops.cpp +++ b/llvm/lib/Target/PowerPC/PPCCTRLoops.cpp @@ -233,6 +233,13 @@ bool PPCCTRLoops::mightUseCTR(const Triple &TT, BasicBlock *BB) { #endif case Intrinsic::longjmp: + + // Exclude eh_sjlj_setjmp; we don't need to exclude eh_sjlj_longjmp + // because, although it does clobber the counter register, the + // control can't then return to inside the loop unless there is also + // an eh_sjlj_setjmp. + case Intrinsic::eh_sjlj_setjmp: + case Intrinsic::memcpy: case Intrinsic::memmove: case Intrinsic::memset: diff --git a/llvm/lib/Target/PowerPC/PPCInstr64Bit.td b/llvm/lib/Target/PowerPC/PPCInstr64Bit.td index e7bb259..f04820a 100644 --- a/llvm/lib/Target/PowerPC/PPCInstr64Bit.td +++ b/llvm/lib/Target/PowerPC/PPCInstr64Bit.td @@ -280,6 +280,7 @@ def MFCR8 : XFXForm_3<31, 19, (outs g8rc:$rT), (ins), } // neverHasSideEffects = 1 let hasSideEffects = 1, isBarrier = 1, usesCustomInserter = 1 in { + let Defs = [CTR8] in def EH_SjLj_SetJmp64 : Pseudo<(outs gprc:$dst), (ins memr:$buf), "#EH_SJLJ_SETJMP64", [(set i32:$dst, (PPCeh_sjlj_setjmp addr:$buf))]>, diff --git a/llvm/lib/Target/PowerPC/PPCInstrInfo.td b/llvm/lib/Target/PowerPC/PPCInstrInfo.td index d4969f6..398a11b 100644 --- a/llvm/lib/Target/PowerPC/PPCInstrInfo.td +++ b/llvm/lib/Target/PowerPC/PPCInstrInfo.td @@ -1093,6 +1093,7 @@ def TAILBA : IForm<18, 0, 0, (outs), (ins abscalltarget:$dst), } let hasSideEffects = 1, isBarrier = 1, usesCustomInserter = 1 in { + let Defs = [CTR] in def EH_SjLj_SetJmp32 : Pseudo<(outs gprc:$dst), (ins memr:$buf), "#EH_SJLJ_SETJMP32", [(set i32:$dst, (PPCeh_sjlj_setjmp addr:$buf))]>, diff --git a/llvm/test/CodeGen/PowerPC/sj-ctr-loop.ll b/llvm/test/CodeGen/PowerPC/sj-ctr-loop.ll new file mode 100644 index 0000000..1866bcd --- /dev/null +++ b/llvm/test/CodeGen/PowerPC/sj-ctr-loop.ll @@ -0,0 +1,50 @@ +; RUN: llc -mtriple=powerpc64-unknown-linux-gnu < %s | 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-f128:128:128-v128:128:128-n32:64" +target triple = "powerpc64-unknown-linux-gnu" + +%struct.__jmp_buf_tag.1.15.17.21.25.49.53.55 = type { [64 x i64], i32, %struct.__sigset_t.0.14.16.20.24.48.52.54, [8 x i8] } +%struct.__sigset_t.0.14.16.20.24.48.52.54 = type { [16 x i64] } + +@env_sigill = external global [1 x %struct.__jmp_buf_tag.1.15.17.21.25.49.53.55], align 16 + +; CHECK-LABEL: @main +; CHECK-NOT: mtctr + +; Function Attrs: nounwind +define void @main() #0 { +entry: + br i1 undef, label %return, label %if.end + +if.end: ; preds = %entry + br i1 undef, label %for.body.lr.ph, label %for.end.thread + +for.end.thread: ; preds = %if.end + br label %return + +for.body.lr.ph: ; preds = %if.end + br label %for.body + +for.cond: ; preds = %for.body + %cmp2 = icmp slt i32 %inc, undef + br i1 %cmp2, label %for.body, label %for.end + +for.body: ; preds = %for.cond, %for.body.lr.ph + %i.032 = phi i32 [ 0, %for.body.lr.ph ], [ %inc, %for.cond ] + %0 = call i32 @llvm.eh.sjlj.setjmp(i8* bitcast ([1 x %struct.__jmp_buf_tag.1.15.17.21.25.49.53.55]* @env_sigill to i8*)) + %inc = add nsw i32 %i.032, 1 + br i1 false, label %if.else, label %for.cond + +if.else: ; preds = %for.body + unreachable + +for.end: ; preds = %for.cond + unreachable + +return: ; preds = %for.end.thread, %entry + ret void +} + +; Function Attrs: nounwind +declare i32 @llvm.eh.sjlj.setjmp(i8*) #0 + +attributes #0 = { nounwind } -- 2.7.4