[llvm-branch-commits] [llvm] opt: Try to respect target-abi command line option (PR #169604)

[Matt Arsenault via llvm-branch-commits]

https://github.com/arsenm created https://github.com/llvm/llvm-project/pull/169604

Mips seems kind of broken with these options. n32 seems to
override the 64-bit arch with 32-bit pointers, and trying
to use any 32-bit mips triple also just errors with any
options.

>From 7f4794d665fe34c66ee25521a325d81f6ec925ee Mon Sep 17 00:00:00 2001
From: Matt Arsenault <Matthew.Arsenault at amd.com>
Date: Tue, 25 Nov 2025 22:59:58 -0500
Subject: [PATCH] opt: Try to respect target-abi command line option

Mips seems kind of broken with these options. n32 seems to
override the 64-bit arch with 32-bit pointers, and trying
to use any 32-bit mips triple also just errors with any
options.
---
 llvm/include/llvm/MC/MCTargetOptionsCommandFlags.h  |  5 +++--
 llvm/lib/MC/MCTargetOptionsCommandFlags.cpp         | 11 +++++++++--
 llvm/test/tools/opt/infer-data-layout-target-abi.ll |  8 ++++++++
 llvm/tools/opt/optdriver.cpp                        |  9 +++++----
 4 files changed, 25 insertions(+), 8 deletions(-)
 create mode 100644 llvm/test/tools/opt/infer-data-layout-target-abi.ll

diff --git a/llvm/include/llvm/MC/MCTargetOptionsCommandFlags.h b/llvm/include/llvm/MC/MCTargetOptionsCommandFlags.h
index adfdccdb5ab77..168131b43cca8 100644
--- a/llvm/include/llvm/MC/MCTargetOptionsCommandFlags.h
+++ b/llvm/include/llvm/MC/MCTargetOptionsCommandFlags.h
@@ -22,6 +22,7 @@ namespace llvm {
 
 class MCTargetOptions;
 enum class EmitDwarfUnwindType;
+class StringRef;
 
 namespace mc {
 
@@ -62,9 +63,9 @@ LLVM_ABI bool getX86RelaxRelocations();
 
 LLVM_ABI bool getX86Sse2Avx();
 
-LLVM_ABI std::string getABIName();
+LLVM_ABI StringRef getABIName();
 
-LLVM_ABI std::string getAsSecureLogFile();
+LLVM_ABI StringRef getAsSecureLogFile();
 
 /// Create this object with static storage to register mc-related command
 /// line options.
diff --git a/llvm/lib/MC/MCTargetOptionsCommandFlags.cpp b/llvm/lib/MC/MCTargetOptionsCommandFlags.cpp
index ff95ff78fd53a..460667b9c7c08 100644
--- a/llvm/lib/MC/MCTargetOptionsCommandFlags.cpp
+++ b/llvm/lib/MC/MCTargetOptionsCommandFlags.cpp
@@ -24,6 +24,13 @@ using namespace llvm;
     return *NAME##View;                                                        \
   }
 
+#define MCSTROPT(TY, NAME)                                                     \
+  static cl::opt<std::string> *NAME##View;                                     \
+  StringRef llvm::mc::get##NAME() {                                            \
+    assert(NAME##View && "RegisterMCTargetOptionsFlags not created.");         \
+    return *NAME##View;                                                        \
+  }
+
 #define MCOPT_EXP(TY, NAME)                                                    \
   MCOPT(TY, NAME)                                                              \
   std::optional<TY> llvm::mc::getExplicit##NAME() {                            \
@@ -52,8 +59,8 @@ MCOPT(bool, Crel)
 MCOPT(bool, ImplicitMapSyms)
 MCOPT(bool, X86RelaxRelocations)
 MCOPT(bool, X86Sse2Avx)
-MCOPT(std::string, ABIName)
-MCOPT(std::string, AsSecureLogFile)
+MCSTROPT(std::string, ABIName)
+MCSTROPT(std::string, AsSecureLogFile)
 
 llvm::mc::RegisterMCTargetOptionsFlags::RegisterMCTargetOptionsFlags() {
 #define MCBINDOPT(NAME)                                                        \
diff --git a/llvm/test/tools/opt/infer-data-layout-target-abi.ll b/llvm/test/tools/opt/infer-data-layout-target-abi.ll
new file mode 100644
index 0000000000000..4a1ec9305ab6a
--- /dev/null
+++ b/llvm/test/tools/opt/infer-data-layout-target-abi.ll
@@ -0,0 +1,8 @@
+;; Check that we infer the correct datalayout from a target triple
+; RUN: opt -mtriple=mips64-- -S -passes=no-op-module -target-abi=n32 < %s | FileCheck -check-prefix=N32 %s
+; RUN: opt -mtriple=mips64-- -S -passes=no-op-module -target-abi=n64 < %s | FileCheck -check-prefix=N64 %s
+
+target datalayout = ""
+
+; N32: target datalayout = "E-m:e-p:32:32-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"
+; N64: target datalayout = "E-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"
diff --git a/llvm/tools/opt/optdriver.cpp b/llvm/tools/opt/optdriver.cpp
index 63c47151389b5..f8be9f16aada6 100644
--- a/llvm/tools/opt/optdriver.cpp
+++ b/llvm/tools/opt/optdriver.cpp
@@ -37,6 +37,7 @@
 #include "llvm/InitializePasses.h"
 #include "llvm/LinkAllIR.h"
 #include "llvm/LinkAllPasses.h"
+#include "llvm/MC/MCTargetOptionsCommandFlags.h"
 #include "llvm/MC/TargetRegistry.h"
 #include "llvm/Passes/PassPlugin.h"
 #include "llvm/Remarks/HotnessThresholdParser.h"
@@ -516,6 +517,8 @@ optMain(int argc, char **argv,
 
   codegen::MaybeEnableStatistics();
 
+  StringRef ABIName = mc::getABIName(); // FIXME: Handle module flag.
+
   // Load the input module...
   auto SetDataLayout = [&](StringRef IRTriple,
                            StringRef IRLayout) -> std::optional<std::string> {
@@ -541,7 +544,7 @@ optMain(int argc, char **argv,
 
     Triple TT(TripleStr);
 
-    std::string Str = TT.computeDataLayout();
+    std::string Str = TT.computeDataLayout(ABIName);
     if (Str.empty()) {
       errs() << argv[0]
              << ": warning: failed to infer data layout from target triple\n";
@@ -677,9 +680,7 @@ optMain(int argc, char **argv,
 
   RTLIB::RuntimeLibcallsInfo RTLCI(ModuleTriple, codegen::getExceptionModel(),
                                    codegen::getFloatABIForCalls(),
-                                   codegen::getEABIVersion(),
-                                   "", // FIXME: Get ABI name from MCOptions
-                                   VecLib);
+                                   codegen::getEABIVersion(), ABIName, VecLib);
 
   // The -disable-simplify-libcalls flag actually disables all builtin optzns.
   if (DisableSimplifyLibCalls)