[llvm] [SystemZ] Remove getInliningThresholdMultiplier() override (PR #94612)

[Nikita Popov via llvm-commits]

https://github.com/nikic created https://github.com/llvm/llvm-project/pull/94612

Using this TTI hook is only appropriate for GPU targets that need to maximally flatten all functions.

The inlining threshold multiplier should not be increased for ordinary targets -- while this may increase benchmark scores, it can also result in large code size increases and runaway inlining, resulting in build OOM/timeouts.

>From 5c94dc5cc90568a8e8e70407ec8877d255f6a74b Mon Sep 17 00:00:00 2001
From: Nikita Popov <npopov at redhat.com>
Date: Thu, 6 Jun 2024 14:57:04 +0200
Subject: [PATCH] [SystemZ] Remove getInliningThresholdMultiplier() override

Using this TTI hook is only appropriate for GPU targets that need
to maximally flatten all functions.

The inlining threshold multiplier should not be increased for
ordinary targets -- while this may increase benchmark scores, it
can also result in large code size increases and runaway inlining,
resulting in build OOM/timeouts.
---
 llvm/lib/Target/SystemZ/SystemZTargetTransformInfo.h | 1 -
 1 file changed, 1 deletion(-)

diff --git a/llvm/lib/Target/SystemZ/SystemZTargetTransformInfo.h b/llvm/lib/Target/SystemZ/SystemZTargetTransformInfo.h
index 3cf4a69ac2818..18effe6950e6c 100644
--- a/llvm/lib/Target/SystemZ/SystemZTargetTransformInfo.h
+++ b/llvm/lib/Target/SystemZ/SystemZTargetTransformInfo.h
@@ -38,7 +38,6 @@ class SystemZTTIImpl : public BasicTTIImplBase<SystemZTTIImpl> {
   /// \name Scalar TTI Implementations
   /// @{
 
-  unsigned getInliningThresholdMultiplier() const { return 3; }
   unsigned adjustInliningThreshold(const CallBase *CB) const;
 
   InstructionCost getIntImmCost(const APInt &Imm, Type *Ty,