From 4f331ff0d30a81ae5c41ad5a35964398996930a1 Mon Sep 17 00:00:00 2001 From: Derek Schuff Date: Fri, 11 Dec 2015 18:55:34 +0000 Subject: [PATCH] [WebAssembly] Fix ADJCALLSTACKDOWN/UP use/defs Summary: ADJCALLSTACK{DOWN,UP} (aka CALLSEQ_{START,END}) MIs are supposed to use and def the stack pointer. Since they do not, all the nodes are being eliminated by DeadMachineInstructionElim, so they aren't in the IR when PrologEpilogInserter/eliminateCallFramePseudo needs them. This change fixes that, but since RegStackify will not stackify across them (and it runs early, before PEI), change LowerCall to only emit them when the call frame size is > 0. That makes the current code work the same way and makes code handled by D15344 also work the same way. We can expand the condition beyond NumBytes > 0 in the future if needed. Reviewers: sunfish, jfb Subscribers: jfb, dschuff, llvm-commits Differential Revision: http://reviews.llvm.org/D15459 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255356 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/WebAssembly/WebAssemblyISelLowering.cpp | 13 +++++++++---- lib/Target/WebAssembly/WebAssemblyInstrCall.td | 2 +- 2 files changed, 10 insertions(+), 5 deletions(-) diff --git a/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp b/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp index 4ef0846d311..76df63b5407 100644 --- a/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp +++ b/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp @@ -359,8 +359,11 @@ WebAssemblyTargetLowering::LowerCall(CallLoweringInfo &CLI, unsigned NumBytes = CCInfo.getAlignedCallFrameSize(); - auto NB = DAG.getConstant(NumBytes, DL, PtrVT, true); - Chain = DAG.getCALLSEQ_START(Chain, NB, DL); + SDValue NB; + if (NumBytes) { + NB = DAG.getConstant(NumBytes, DL, PtrVT, true); + Chain = DAG.getCALLSEQ_START(Chain, NB, DL); + } if (IsVarArg) { // For non-fixed arguments, next emit stores to store the argument values @@ -420,8 +423,10 @@ WebAssemblyTargetLowering::LowerCall(CallLoweringInfo &CLI, Chain = Res.getValue(1); } - SDValue Unused = DAG.getUNDEF(PtrVT); - Chain = DAG.getCALLSEQ_END(Chain, NB, Unused, SDValue(), DL); + if (NumBytes) { + SDValue Unused = DAG.getUNDEF(PtrVT); + Chain = DAG.getCALLSEQ_END(Chain, NB, Unused, SDValue(), DL); + } return Chain; } diff --git a/lib/Target/WebAssembly/WebAssemblyInstrCall.td b/lib/Target/WebAssembly/WebAssemblyInstrCall.td index 0587c0b6613..6ea8cec7397 100644 --- a/lib/Target/WebAssembly/WebAssemblyInstrCall.td +++ b/lib/Target/WebAssembly/WebAssemblyInstrCall.td @@ -18,7 +18,7 @@ let Defs = [ARGUMENTS] in { // Call sequence markers. These have an immediate which represents the amount of // stack space to allocate or free, which is used for varargs lowering. -let isCodeGenOnly = 1 in { +let Uses = [SP32, SP64], Defs = [SP32, SP64], isCodeGenOnly = 1 in { def ADJCALLSTACKDOWN : I<(outs), (ins i32imm:$amt), [(WebAssemblycallseq_start timm:$amt)]>; def ADJCALLSTACKUP : I<(outs), (ins i32imm:$amt), -- 2.34.1