[RISCV] Enable merging of external globals by default

Author: asb

llvm/lib/Target/RISCV/RISCVTargetMachine.cpp

@@ -51,12 +51,9 @@ static cl::opt<cl::boolOrDefault>
     EnableGlobalMerge("riscv-enable-global-merge", cl::Hidden,
                       cl::desc("Enable the global merge pass"));
 
-static cl::opt<bool> ForceEnableGlobalMergeExternalGlobals(
-    "riscv-force-enable-global-merge-external-globals", cl::Hidden,
-    cl::init(false),
-    cl::desc(
-        "If the global merge pass is enabled, force enable global merging of "
-        "external globals (overriding any logic that might disable it)"));
+static cl::opt<bool> DisableGlobalMergeExternalGlobals(
+    "riscv-disable-global-merge-external-globals", cl::Hidden, cl::init(false),
+    cl::desc("Disable global merging of external globals"));
 
 static cl::opt<bool>
     EnableMachineCombiner("riscv-enable-machine-combiner",
@@ -484,7 +481,7 @@ bool RISCVPassConfig::addPreISel() {
     addPass(createGlobalMergePass(TM, /* MaxOffset */ 2047,
                                   /* OnlyOptimizeForSize */ false,
                                   /* MergeExternalByDefault */
-                                  ForceEnableGlobalMergeExternalGlobals));
+                                  !DisableGlobalMergeExternalGlobals));
   }
 
   return false;

llvm/test/CodeGen/RISCV/global-merge-minsize-smalldata-nonzero.ll

@@ -1,8 +1,7 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
-; RUN: llc -mtriple=riscv64 -riscv-force-enable-global-merge-external-globals \
-; RUN:   -verify-machineinstrs < %s | FileCheck %s -check-prefix=SMALL-DATA
-; RUN: llc -mtriple=riscv64 -global-merge-min-data-size=0 \
-; RUN:   -riscv-force-enable-global-merge-external-globals -verify-machineinstrs < %s \
+; RUN: llc -mtriple=riscv64 -verify-machineinstrs < %s \
+; RUN:   | FileCheck %s -check-prefix=SMALL-DATA
+; RUN: llc -mtriple=riscv64 -global-merge-min-data-size=0 -verify-machineinstrs < %s \
 ; RUN:   | FileCheck %s -check-prefix=MINSIZE
 
 @ig1 = internal global i32 0, align 4

llvm/test/CodeGen/RISCV/global-merge-minsize-smalldata-zero.ll

@@ -1,8 +1,7 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
-; RUN: llc -mtriple=riscv32 -riscv-force-enable-global-merge-external-globals \
-; RUN:   -verify-machineinstrs < %s | FileCheck %s -check-prefix=SMALL-DATA
-; RUN: llc -mtriple=riscv64 -global-merge-min-data-size=5 \
-; RUN:   -riscv-force-enable-global-merge-external-globals  -verify-machineinstrs < %s \
+; RUN: llc -mtriple=riscv32 -verify-machineinstrs < %s \
+; RUN:   | FileCheck %s -check-prefix=SMALL-DATA
+; RUN: llc -mtriple=riscv64 -global-merge-min-data-size=5 -verify-machineinstrs < %s \
 ; RUN:   | FileCheck %s -check-prefix=MINSIZE
 
 @ig1 = internal global i32 0, align 4

llvm/test/CodeGen/RISCV/global-merge-minsize.ll

@@ -1,8 +1,8 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
-; RUN: llc -mtriple=riscv32 -riscv-force-enable-global-merge-external-globals \
+; RUN: llc -mtriple=riscv32 \
 ; RUN:   -verify-machineinstrs < %s | FileCheck %s -check-prefix=RV32
 ; RUN: llc -mtriple=riscv32 -global-merge-min-data-size=5 \
-; RUN:   -riscv-force-enable-global-merge-external-globals -verify-machineinstrs < %s | FileCheck %s -check-prefix=RV32-MINSIZE
+; RUN:   -verify-machineinstrs < %s | FileCheck %s -check-prefix=RV32-MINSIZE
 
 @ig1 = internal global i32 0, align 4
 @ig2 = internal global i32 0, align 4

llvm/test/CodeGen/RISCV/global-merge-offset.ll

@@ -1,12 +1,12 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
 ; RUN: sed 's/ArrSize/100/g' %s | llc -mtriple=riscv32 \
-; RUN:   -riscv-force-enable-global-merge-external-globals -verify-machineinstrs | FileCheck %s
+; RUN:   -verify-machineinstrs | FileCheck %s
 ; RUN: sed 's/ArrSize/100/g' %s | llc -mtriple=riscv64 \
-; RUN:   -riscv-force-enable-global-merge-external-globals -verify-machineinstrs | FileCheck %s
+; RUN:   -verify-machineinstrs | FileCheck %s
 ; RUN: sed 's/ArrSize/101/g' %s | llc -mtriple=riscv32 \
-; RUN:   -riscv-force-enable-global-merge-external-globals -verify-machineinstrs | FileCheck %s -check-prefix=CHECK-TOOBIG
+; RUN:   -verify-machineinstrs | FileCheck %s -check-prefix=CHECK-TOOBIG
 ; RUN: sed 's/ArrSize/101/g' %s | llc -mtriple=riscv64 \
-; RUN:   -riscv-force-enable-global-merge-external-globals -verify-machineinstrs | FileCheck %s -check-prefix=CHECK-TOOBIG
+; RUN:   -verify-machineinstrs | FileCheck %s -check-prefix=CHECK-TOOBIG
 
 ; This test demonstrates that the MaxOffset is set correctly for RISC-V by
 ; constructing an input that is at the limit and comparing.

llvm/test/CodeGen/RISCV/global-merge.ll

@@ -1,11 +1,11 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
-; RUN: llc -mtriple=riscv32 -verify-machineinstrs < %s | FileCheck %s
-; RUN: llc -mtriple=riscv64 -verify-machineinstrs < %s | FileCheck %s
-; RUN: llc -mtriple=riscv32 \
-; RUN:     -riscv-force-enable-global-merge-external-globals -verify-machineinstrs < %s \
+; RUN: llc -mtriple=riscv32 -riscv-disable-global-merge-external-globals \
+; RUN:     -verify-machineinstrs < %s | FileCheck %s
+; RUN: llc -mtriple=riscv64 -riscv-disable-global-merge-external-globals \
+; RUN:     -verify-machineinstrs < %s | FileCheck %s
+; RUN: llc -mtriple=riscv32 -verify-machineinstrs < %s \
 ; RUN:   | FileCheck -check-prefix=CHECK-WEXTERN %s
-; RUN: llc -mtriple=riscv64 \
-; RUN:     -riscv-force-enable-global-merge-external-globals -verify-machineinstrs < %s \
+; RUN: llc -mtriple=riscv64 -verify-machineinstrs < %s \
 ; RUN:   | FileCheck -check-prefix=CHECK-WEXTERN %s
 
 @ig1 = internal global i32 0, align 4