[Lldb-commits] [lldb] f6b6234 - [lldb][AArch64] Remove bool return from UpdateARM64SVERegistersInfos

[David Spickett via lldb-commits]

Author: David Spickett
Date: 2023-09-05T10:03:50+01:00
New Revision: f6b6234d14d2fa379a1f2d6b54259cac89a7fc73

URL: https://github.com/llvm/llvm-project/commit/f6b6234d14d2fa379a1f2d6b54259cac89a7fc73
DIFF: https://github.com/llvm/llvm-project/commit/f6b6234d14d2fa379a1f2d6b54259cac89a7fc73.diff

LOG: [lldb][AArch64] Remove bool return from UpdateARM64SVERegistersInfos

This always succeeds. While I'm here, document why we check the size
of p0 against the value of VG.

Reviewed By: omjavaid

Differential Revision: https://reviews.llvm.org/D157845

Added: 
    

Modified: 
    lldb/source/Plugins/Process/gdb-remote/GDBRemoteRegisterContext.cpp
    lldb/source/Plugins/Process/gdb-remote/GDBRemoteRegisterContext.h

Removed: 
    


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diff  --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteRegisterContext.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteRegisterContext.cpp
index e8606ddae5674a7..bd9211bbaad5293 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteRegisterContext.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteRegisterContext.cpp
@@ -772,27 +772,28 @@ bool GDBRemoteRegisterContext::AArch64SVEReconfigure() {
   uint32_t vg_reg_num = reg_info->kinds[eRegisterKindLLDB];
   uint64_t vg_reg_value = ReadRegisterAsUnsigned(vg_reg_num, fail_value);
 
-  if (vg_reg_value != fail_value && vg_reg_value <= 32) {
-    const RegisterInfo *reg_info = m_reg_info_sp->GetRegisterInfo("p0");
-    if (!reg_info || vg_reg_value == reg_info->byte_size)
-      return false;
+  if (vg_reg_value == fail_value || vg_reg_value > 32)
+    return false;
 
-    if (m_reg_info_sp->UpdateARM64SVERegistersInfos(vg_reg_value)) {
-      // Make a heap based buffer that is big enough to store all registers
-      m_reg_data.SetData(std::make_shared<DataBufferHeap>(
-          m_reg_info_sp->GetRegisterDataByteSize(), 0));
-      m_reg_data.SetByteOrder(GetByteOrder());
+  reg_info = m_reg_info_sp->GetRegisterInfo("p0");
+  // Predicate registers have 1 bit per byte in the vector so their size is
+  // VL / 8. VG is in units of 8 bytes already, so if the size of p0 == VG
+  // already, we do not have to reconfigure.
+  if (!reg_info || vg_reg_value == reg_info->byte_size)
+    return false;
 
-      InvalidateAllRegisters();
+  m_reg_info_sp->UpdateARM64SVERegistersInfos(vg_reg_value);
+  // Make a heap based buffer that is big enough to store all registers
+  m_reg_data.SetData(std::make_shared<DataBufferHeap>(
+      m_reg_info_sp->GetRegisterDataByteSize(), 0));
+  m_reg_data.SetByteOrder(GetByteOrder());
 
-      return true;
-    }
-  }
+  InvalidateAllRegisters();
 
-  return false;
+  return true;
 }
 
-bool GDBRemoteDynamicRegisterInfo::UpdateARM64SVERegistersInfos(uint64_t vg) {
+void GDBRemoteDynamicRegisterInfo::UpdateARM64SVERegistersInfos(uint64_t vg) {
   // SVE Z register size is vg x 8 bytes.
   uint32_t z_reg_byte_size = vg * 8;
 
@@ -813,5 +814,4 @@ bool GDBRemoteDynamicRegisterInfo::UpdateARM64SVERegistersInfos(uint64_t vg) {
 
   // Re-calculate register offsets
   ConfigureOffsets();
-  return true;
 }

diff  --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteRegisterContext.h b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteRegisterContext.h
index d185cb5aede1e50..a4fa18327047c08 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteRegisterContext.h
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteRegisterContext.h
@@ -38,7 +38,7 @@ class GDBRemoteDynamicRegisterInfo final : public DynamicRegisterInfo {
 
   ~GDBRemoteDynamicRegisterInfo() override = default;
 
-  bool UpdateARM64SVERegistersInfos(uint64_t vg);
+  void UpdateARM64SVERegistersInfos(uint64_t vg);
 };
 
 class GDBRemoteRegisterContext : public RegisterContext {