[llvm-branch-commits] [llvm] PR for llvm/llvm-project#80577 (PR #80578)

[via llvm-branch-commits]

https://github.com/llvmbot created https://github.com/llvm/llvm-project/pull/80578

resolves llvm/llvm-project#80577

>From bb71add47cd69b184b0fe1b72bd44e8a36a74367 Mon Sep 17 00:00:00 2001
From: wanglei <wanglei at loongson.cn>
Date: Fri, 26 Jan 2024 10:24:07 +0800
Subject: [PATCH] [LoongArch] Fixing the incorrect return value of
 LoongArchTTIImpl::getRegisterBitWidth (#79441)

When we do not enable vector features, we should return the default
value (`TargetTransformInfoImplBase::getRegisterBitWidth`) instead of
zero.

This should fix the LoongArch [buildbot
breakage](https://lab.llvm.org/staging/#/builders/5/builds/486) from
#78943.

(cherry picked from commit 1e9924c1f248bbddcb95d82a59708d617297dad3)
---
 .../Target/LoongArch/LoongArchTargetTransformInfo.cpp | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/llvm/lib/Target/LoongArch/LoongArchTargetTransformInfo.cpp b/llvm/lib/Target/LoongArch/LoongArchTargetTransformInfo.cpp
index 04349aa52b540..d47dded9ea6ec 100644
--- a/llvm/lib/Target/LoongArch/LoongArchTargetTransformInfo.cpp
+++ b/llvm/lib/Target/LoongArch/LoongArchTargetTransformInfo.cpp
@@ -21,17 +21,20 @@ using namespace llvm;
 
 TypeSize LoongArchTTIImpl::getRegisterBitWidth(
     TargetTransformInfo::RegisterKind K) const {
+  TypeSize DefSize = TargetTransformInfoImplBase::getRegisterBitWidth(K);
   switch (K) {
   case TargetTransformInfo::RGK_Scalar:
     return TypeSize::getFixed(ST->is64Bit() ? 64 : 32);
   case TargetTransformInfo::RGK_FixedWidthVector:
-    if (ST->hasExtLASX() && ST->hasExpAutoVec())
+    if (!ST->hasExpAutoVec())
+      return DefSize;
+    if (ST->hasExtLASX())
       return TypeSize::getFixed(256);
-    if (ST->hasExtLSX() && ST->hasExpAutoVec())
+    if (ST->hasExtLSX())
       return TypeSize::getFixed(128);
-    return TypeSize::getFixed(0);
+    [[fallthrough]];
   case TargetTransformInfo::RGK_ScalableVector:
-    return TypeSize::getScalable(0);
+    return DefSize;
   }
 
   llvm_unreachable("Unsupported register kind");