Add extra operand to CALLSEQ_START to keep frame part set up previously

Using arguments with attribute inalloca creates problems for verification
of machine representation. This attribute instructs the backend that the
argument is prepared in stack prior to  CALLSEQ_START..CALLSEQ_END
sequence (see http://llvm.org/docs/InAlloca.htm for details). Frame size
stored in CALLSEQ_START in this case does not count the size of this
argument. However CALLSEQ_END still keeps total frame size, as caller can
be responsible for cleanup of entire frame. So CALLSEQ_START and
CALLSEQ_END keep different frame size and the difference is treated by
MachineVerifier as stack error. Currently there is no way to distinguish
this case from actual errors.

This patch adds additional argument to CALLSEQ_START and its
target-specific counterparts to keep size of stack that is set up prior to
the call frame sequence. This argument allows MachineVerifier to calculate
actual frame size associated with frame setup instruction and correctly
process the case of inalloca arguments.

The changes made by the patch are:
- Frame setup instructions get the second mandatory argument. It
  affects all targets that use frame pseudo instructions and touched many
  files although the changes are uniform.
- Access to frame properties are implemented using special instructions
  rather than calls getOperand(N).getImm(). For X86 and ARM such
  replacement was made previously.
- Changes that reflect appearance of additional argument of frame setup
  instruction. These involve proper instruction initialization and
  methods that access instruction arguments.
- MachineVerifier retrieves frame size using method, which reports sum of
  frame parts initialized inside frame instruction pair and outside it.

The patch implements approach proposed by Quentin Colombet in
https://bugs.llvm.org/show_bug.cgi?id=27481#c1.
It fixes 9 tests failed with machine verifier enabled and listed
in PR27481.

Differential Revision: https://reviews.llvm.org/D32394

llvm-svn: 302527

2 files changed, 4 insertions, 3 deletions

diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyInstrCall.td b/llvm/lib/Target/WebAssembly/WebAssemblyInstrCall.td
index 73d1d4be293..6b45839c14b 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyInstrCall.td
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyInstrCall.td
@@ -19,8 +19,8 @@ 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 Uses = [SP32, SP64], Defs = [SP32, SP64], isCodeGenOnly = 1 in {
-def ADJCALLSTACKDOWN : I<(outs), (ins i32imm:$amt),
-                         [(WebAssemblycallseq_start timm:$amt)]>;
+def ADJCALLSTACKDOWN : I<(outs), (ins i32imm:$amt, i32imm:$amt2),
+                         [(WebAssemblycallseq_start timm:$amt, timm:$amt2)]>;
 def ADJCALLSTACKUP : I<(outs), (ins i32imm:$amt, i32imm:$amt2),
                        [(WebAssemblycallseq_end timm:$amt, timm:$amt2)]>;
 } // isCodeGenOnly = 1
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.td b/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.td
index a601b575f57..fa2146f7db8 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.td
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.td
@@ -25,7 +25,8 @@ def HasSIMD128 : Predicate<"Subtarget->hasSIMD128()">,
 // WebAssembly-specific DAG Node Types.
 //===----------------------------------------------------------------------===//
 
-def SDT_WebAssemblyCallSeqStart : SDCallSeqStart<[SDTCisVT<0, iPTR>]>;
+def SDT_WebAssemblyCallSeqStart : SDCallSeqStart<[SDTCisVT<0, iPTR>,
+                                                  SDTCisVT<1, iPTR>]>;
 def SDT_WebAssemblyCallSeqEnd :
     SDCallSeqEnd<[SDTCisVT<0, iPTR>, SDTCisVT<1, iPTR>]>;
 def SDT_WebAssemblyCall0    : SDTypeProfile<0, -1, [SDTCisPtrTy<0>]>;