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[AArch64][GlobalISel] Support sibling calls with outgoing arguments

Authored by paquette on Sep 12 2019, 3:10 PM.

Description

[AArch64][GlobalISel] Support sibling calls with outgoing arguments

This adds support for lowering sibling calls with outgoing arguments.

e.g

define void @foo(i32 %a)

Support is ported from AArch64ISelLowering's isEligibleForTailCallOptimization.
The only thing that is missing is a full port of
TargetLowering::parametersInCSRMatch. So, if we're using swiftself,
we'll never tail call.

  • Rename analyzeCallResult to analyzeArgInfo, since the function is now used for both outgoing and incoming arguments
  • Teach OutgoingArgHandler about tail calls. Tail calls use frame indices for stack arguments.
  • Teach lowerFormalArguments to set the bytes in the caller's stack argument area. This is used later to check if the tail call's parameters will fit on the caller's stack.
  • Add areCalleeOutgoingArgsTailCallable to perform the eligibility check on the callee's outgoing arguments.

For testing:

  • Update call-translator-tail-call to verify that we can now tail call with outgoing arguments, use G_FRAME_INDEX for stack arguments, and respect the size of the caller's stack
  • Remove GISel-specific check lines from speculation-hardening.ll, since GISel now tail calls like the other selectors
  • Add a GISel test line to tailcall-string-rvo.ll since we can tail call in that test now
  • Add a GISel test line to tailcall_misched_graph.ll since we tail call there now. Add specific check lines for GISel, since the debug output from the machine-scheduler differs with GlobalISel. The dependency still holds, but the output comes out in a different order.

Differential Revision: https://reviews.llvm.org/D67471

llvm-svn: 371780