From 703fd28e42c8d84b0b7142164cb60ba19fb11c71 Mon Sep 17 00:00:00 2001 From: Kyle Butt Date: Tue, 12 Jan 2016 21:00:43 +0000 Subject: [PATCH] Codegen: [PPC] Handle weighted comparisons when inserting selects. Only non-weighted predicates were handled in PPCInstrInfo::insertSelect. Handle the weighted predicates as well. This latent bug was triggered by r255398, because it added use of the branch-weighted predicates. While here, switch over an enum instead of an int to get the compiler to enforce totality in the future. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257518 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/PowerPC/PPCInstrInfo.cpp | 43 ++++++++++++++----- .../PowerPC/2016-01-07-BranchWeightCrash.ll | 35 +++++++++++++++ 2 files changed, 68 insertions(+), 10 deletions(-) create mode 100644 test/CodeGen/PowerPC/2016-01-07-BranchWeightCrash.ll diff --git a/lib/Target/PowerPC/PPCInstrInfo.cpp b/lib/Target/PowerPC/PPCInstrInfo.cpp index c17603a7718..dcff6ad2486 100644 --- a/lib/Target/PowerPC/PPCInstrInfo.cpp +++ b/lib/Target/PowerPC/PPCInstrInfo.cpp @@ -744,20 +744,43 @@ void PPCInstrInfo::insertSelect(MachineBasicBlock &MBB, "isel is for regular integer GPRs only"); unsigned OpCode = Is64Bit ? PPC::ISEL8 : PPC::ISEL; - unsigned SelectPred = Cond[0].getImm(); + auto SelectPred = static_cast(Cond[0].getImm()); unsigned SubIdx; bool SwapOps; switch (SelectPred) { - default: llvm_unreachable("invalid predicate for isel"); - case PPC::PRED_EQ: SubIdx = PPC::sub_eq; SwapOps = false; break; - case PPC::PRED_NE: SubIdx = PPC::sub_eq; SwapOps = true; break; - case PPC::PRED_LT: SubIdx = PPC::sub_lt; SwapOps = false; break; - case PPC::PRED_GE: SubIdx = PPC::sub_lt; SwapOps = true; break; - case PPC::PRED_GT: SubIdx = PPC::sub_gt; SwapOps = false; break; - case PPC::PRED_LE: SubIdx = PPC::sub_gt; SwapOps = true; break; - case PPC::PRED_UN: SubIdx = PPC::sub_un; SwapOps = false; break; - case PPC::PRED_NU: SubIdx = PPC::sub_un; SwapOps = true; break; + case PPC::PRED_EQ: + case PPC::PRED_EQ_MINUS: + case PPC::PRED_EQ_PLUS: + SubIdx = PPC::sub_eq; SwapOps = false; break; + case PPC::PRED_NE: + case PPC::PRED_NE_MINUS: + case PPC::PRED_NE_PLUS: + SubIdx = PPC::sub_eq; SwapOps = true; break; + case PPC::PRED_LT: + case PPC::PRED_LT_MINUS: + case PPC::PRED_LT_PLUS: + SubIdx = PPC::sub_lt; SwapOps = false; break; + case PPC::PRED_GE: + case PPC::PRED_GE_MINUS: + case PPC::PRED_GE_PLUS: + SubIdx = PPC::sub_lt; SwapOps = true; break; + case PPC::PRED_GT: + case PPC::PRED_GT_MINUS: + case PPC::PRED_GT_PLUS: + SubIdx = PPC::sub_gt; SwapOps = false; break; + case PPC::PRED_LE: + case PPC::PRED_LE_MINUS: + case PPC::PRED_LE_PLUS: + SubIdx = PPC::sub_gt; SwapOps = true; break; + case PPC::PRED_UN: + case PPC::PRED_UN_MINUS: + case PPC::PRED_UN_PLUS: + SubIdx = PPC::sub_un; SwapOps = false; break; + case PPC::PRED_NU: + case PPC::PRED_NU_MINUS: + case PPC::PRED_NU_PLUS: + SubIdx = PPC::sub_un; SwapOps = true; break; case PPC::PRED_BIT_SET: SubIdx = 0; SwapOps = false; break; case PPC::PRED_BIT_UNSET: SubIdx = 0; SwapOps = true; break; } diff --git a/test/CodeGen/PowerPC/2016-01-07-BranchWeightCrash.ll b/test/CodeGen/PowerPC/2016-01-07-BranchWeightCrash.ll new file mode 100644 index 00000000000..65dff12f311 --- /dev/null +++ b/test/CodeGen/PowerPC/2016-01-07-BranchWeightCrash.ll @@ -0,0 +1,35 @@ +; RUN: llc <%s | FileCheck %s +target datalayout = "e-m:e-i64:64-n32:64" +target triple = "powerpc64le-unknown-linux-gnu" + +%struct.buffer_t = type { i64, i8*, [4 x i32], [4 x i32], [4 x i32], i32, i8, i8, [2 x i8] } + +declare i32 @__f1(i8*, %struct.buffer_t* noalias) + +; CHECK-LABEL: f1: +define i32 @f1(i8* %__user_context, %struct.buffer_t* noalias %f1.buffer) { +entry: + br i1 undef, label %"assert succeeded", label %"assert failed", !prof !1 + +"assert failed": ; preds = %entry + br label %destructor_block + +"assert succeeded": ; preds = %entry + %__f1_result = call i32 @__f1(i8* %__user_context, %struct.buffer_t* %f1.buffer) #5 + %0 = icmp eq i32 %__f1_result, 0 + br i1 %0, label %"assert succeeded11", label %"assert failed10", !prof !1 + +destructor_block: ; preds = %"assert succeeded11", %"assert failed10", %"assert failed" + %1 = phi i32 [ undef, %"assert failed" ], [ %__f1_result, %"assert failed10" ], [ 0, %"assert succeeded11" ] + ret i32 %1 + +"assert failed10": ; preds = %"assert succeeded" + br label %destructor_block + +"assert succeeded11": ; preds = %"assert succeeded" + br label %destructor_block +} + +attributes #5 = { nounwind } + +!1 = !{!"branch_weights", i32 1073741824, i32 0} -- 2.34.1