[llvm] [RISCV] Emitting proper atomic ABI tag when Zalasr is enabled (PR #121017)

[Brendan Sweeney via llvm-commits]

https://github.com/mehnadnerd updated https://github.com/llvm/llvm-project/pull/121017

>From ff3ea1413bb04178db7b3b08e9cc7dc1535e38e6 Mon Sep 17 00:00:00 2001
From: Brendan Sweeney <turtwig at utexas.edu>
Date: Mon, 23 Dec 2024 16:28:53 -0800
Subject: [PATCH] [RISCV] Emitting proper atomic ABI tag when Zalasr is enabled
 When Zalasr is enabled, it will emit the A7 atomic ABI tag.

---
 .../Target/RISCV/MCTargetDesc/RISCVTargetStreamer.cpp | 11 +++++++----
 llvm/test/CodeGen/RISCV/attributes.ll                 |  3 +++
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/llvm/lib/Target/RISCV/MCTargetDesc/RISCVTargetStreamer.cpp b/llvm/lib/Target/RISCV/MCTargetDesc/RISCVTargetStreamer.cpp
index 99f57f47835abd..a853181fc7962b 100644
--- a/llvm/lib/Target/RISCV/MCTargetDesc/RISCVTargetStreamer.cpp
+++ b/llvm/lib/Target/RISCV/MCTargetDesc/RISCVTargetStreamer.cpp
@@ -85,10 +85,13 @@ void RISCVTargetStreamer::emitTargetAttributes(const MCSubtargetInfo &STI,
   }
 
   if (RiscvAbiAttr && STI.hasFeature(RISCV::FeatureStdExtA)) {
-    unsigned AtomicABITag = static_cast<unsigned>(
-        STI.hasFeature(RISCV::FeatureNoTrailingSeqCstFence)
-            ? RISCVAttrs::RISCVAtomicAbiTag::A6C
-            : RISCVAttrs::RISCVAtomicAbiTag::A6S);
+    unsigned AtomicABITag;
+    if (STI.hasFeature(RISCV::FeatureStdExtZalasr))
+      AtomicABITag = static_cast<unsigned>(RISCVAttrs::RISCVAtomicAbiTag::A7);
+    else if (STI.hasFeature(RISCV::FeatureNoTrailingSeqCstFence))
+      AtomicABITag = static_cast<unsigned>(RISCVAttrs::RISCVAtomicAbiTag::A6C);
+    else
+      AtomicABITag = static_cast<unsigned>(RISCVAttrs::RISCVAtomicAbiTag::A6S);
     emitAttribute(RISCVAttrs::ATOMIC_ABI, AtomicABITag);
   }
 }
diff --git a/llvm/test/CodeGen/RISCV/attributes.ll b/llvm/test/CodeGen/RISCV/attributes.ll
index 7e55e0590ec598..b1b18fcfd5b007 100644
--- a/llvm/test/CodeGen/RISCV/attributes.ll
+++ b/llvm/test/CodeGen/RISCV/attributes.ll
@@ -155,6 +155,7 @@
 ; RUN: llc -mtriple=riscv64 -mattr=+m,+zmmul %s -o - | FileCheck --check-prefixes=CHECK,RV64MZMMUL %s
 ; RUN: llc -mtriple=riscv64 -mattr=+a,no-trailing-seq-cst-fence --riscv-abi-attributes %s -o - | FileCheck --check-prefixes=CHECK,RV64A,A6C %s
 ; RUN: llc -mtriple=riscv64 -mattr=+a --riscv-abi-attributes %s -o - | FileCheck --check-prefixes=CHECK,RV64A,A6S %s
+; RUN: llc -mtriple=riscv64 -mattr=+a,experimental-zalasr --riscv-abi-attributes %s -o - | FileCheck --check-prefixes=CHECK,RV64ZALASRA,A7 %s
 ; RUN: llc -mtriple=riscv64 -mattr=+b %s -o - | FileCheck --check-prefixes=CHECK,RV64B %s
 ; RUN: llc -mtriple=riscv64 -mattr=+f %s -o - | FileCheck --check-prefixes=CHECK,RV64F %s
 ; RUN: llc -mtriple=riscv64 -mattr=+d %s -o - | FileCheck --check-prefixes=CHECK,RV64D %s
@@ -596,6 +597,7 @@
 ; RV64ZVFBFWMA: .attribute 5, "rv64i2p1_f2p2_zicsr2p0_zfbfmin1p0_zve32f1p0_zve32x1p0_zvfbfmin1p0_zvfbfwma1p0_zvl32b1p0"
 ; RV64ZACAS: .attribute 5, "rv64i2p1_zaamo1p0_zacas1p0"
 ; RV64ZALASR: .attribute 5, "rv64i2p1_zalasr0p1"
+; RV64ZALASRA: .attribute 5, "rv64i2p1_a2p1_zaamo1p0_zalasr0p1_zalrsc1p0"
 ; RV64ZICFILP: .attribute 5, "rv64i2p1_zicfilp1p0_zicsr2p0"
 ; RV64ZABHA: .attribute 5, "rv64i2p1_zaamo1p0_zabha1p0"
 ; RV64ZVBC32E: .attribute 5, "rv64i2p1_zicsr2p0_zvbc32e0p7_zve32x1p0_zvl32b1p0"
@@ -632,4 +634,5 @@ define i8 @atomic_load_i8_seq_cst(ptr %a) nounwind {
   ret i8 %1
 ; A6S: .attribute 14, 2
 ; A6C: .attribute 14, 1
+; A7: .attribute 14, 3
 }