[RISCV] Enable -riscv-enable-sink-fold by default. (#82026)

AArch64 has had it enabled since late November, so hopefully the main
issues have been resolved.

I see a small reduction in dynamic instruction count on every benchmark
in specint2017. The best improvement was 0.3% so nothing amazing.

llvm/lib/Target/RISCV/RISCVTargetMachine.cpp

@@ -84,7 +84,7 @@ static cl::opt<bool> EnableRISCVDeadRegisterElimination(
 static cl::opt<bool>
     EnableSinkFold("riscv-enable-sink-fold",
                    cl::desc("Enable sinking and folding of instruction copies"),
-                   cl::init(false), cl::Hidden);
+                   cl::init(true), cl::Hidden);
 
 static cl::opt<bool>
     EnableLoopDataPrefetch("riscv-enable-loop-data-prefetch", cl::Hidden,

llvm/test/CodeGen/RISCV/fold-addi-loadstore.ll

@@ -1,12 +1,12 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
 ; RUN: llc -mtriple=riscv32 -verify-machineinstrs < %s \
-; RUN:   -riscv-enable-sink-fold | FileCheck -check-prefix=RV32I %s
+; RUN:   | FileCheck -check-prefix=RV32I %s
 ; RUN: llc -mtriple=riscv32 -verify-machineinstrs -code-model=medium < %s \
-; RUN:   -riscv-enable-sink-fold | FileCheck -check-prefix=RV32I-MEDIUM %s
+; RUN:   | FileCheck -check-prefix=RV32I-MEDIUM %s
 ; RUN: llc -mtriple=riscv64 -verify-machineinstrs < %s \
-; RUN:   -riscv-enable-sink-fold | FileCheck -check-prefix=RV64I %s
+; RUN:   | FileCheck -check-prefix=RV64I %s
 ; RUN: llc -mtriple=riscv64 -verify-machineinstrs -code-model=medium < %s \
-; RUN:   -riscv-enable-sink-fold | FileCheck -check-prefix=RV64I-MEDIUM %s
+; RUN:   | FileCheck -check-prefix=RV64I-MEDIUM %s
 
 ; We can often fold an ADDI into the offset of load/store instructions:
 ;   (load (addi base, off1), off2) -> (load base, off1+off2)

llvm/test/CodeGen/RISCV/rvv/fixed-vectors-masked-gather.ll

@@ -1,12 +1,12 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
 ; RUN: llc -mtriple=riscv32 -mattr=+m,+d,+zfh,+zvfh,+v -target-abi=ilp32d \
-; RUN:     -riscv-enable-sink-fold -verify-machineinstrs < %s | FileCheck %s --check-prefixes=CHECK,RV32,RV32V
+; RUN:     -verify-machineinstrs < %s | FileCheck %s --check-prefixes=CHECK,RV32,RV32V
 ; RUN: llc -mtriple=riscv64 -mattr=+m,+d,+zfh,+zvfh,+v -target-abi=lp64d \
-; RUN:     -riscv-enable-sink-fold -verify-machineinstrs < %s | FileCheck %s --check-prefixes=CHECK,RV64,RV64V
+; RUN:     -verify-machineinstrs < %s | FileCheck %s --check-prefixes=CHECK,RV64,RV64V
 ; RUN: llc -mtriple=riscv32 -mattr=+m,+d,+zfh,+zvfh,+zve32f,+zvl128b -target-abi=ilp32d \
-; RUN:     -riscv-enable-sink-fold -verify-machineinstrs < %s | FileCheck %s --check-prefixes=CHECK,RV32,RV32ZVE32F
+; RUN:     -verify-machineinstrs < %s | FileCheck %s --check-prefixes=CHECK,RV32,RV32ZVE32F
 ; RUN: llc -mtriple=riscv64 -mattr=+m,+d,+zfh,+zvfh,+zve32f,+zvl128b -target-abi=lp64d \
-; RUN:     -riscv-enable-sink-fold -verify-machineinstrs < %s | FileCheck %s --check-prefixes=CHECK,RV64,RV64ZVE32F
+; RUN:     -verify-machineinstrs < %s | FileCheck %s --check-prefixes=CHECK,RV64,RV64ZVE32F
 
 declare <1 x i8> @llvm.masked.gather.v1i8.v1p0(<1 x ptr>, i32, <1 x i1>, <1 x i8>)
 

llvm/test/CodeGen/RISCV/split-offsets.ll

@@ -1,7 +1,7 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
-; RUN: llc -mtriple=riscv32 -verify-machineinstrs -riscv-enable-sink-fold < %s \
+; RUN: llc -mtriple=riscv32 -verify-machineinstrs < %s \
 ; RUN:   | FileCheck %s -check-prefix=RV32I
-; RUN: llc -mtriple=riscv64 -verify-machineinstrs -riscv-enable-sink-fold < %s \
+; RUN: llc -mtriple=riscv64 -verify-machineinstrs < %s \
 ; RUN:   | FileCheck %s -check-prefix=RV64I
 
 ; Check that memory accesses to array elements with large offsets have those

llvm/test/CodeGen/RISCV/srem-vector-lkk.ll

@@ -1,11 +1,11 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
-; RUN: llc -mtriple=riscv32 -verify-machineinstrs -riscv-enable-sink-fold < %s \
+; RUN: llc -mtriple=riscv32 -verify-machineinstrs < %s \
 ; RUN:   | FileCheck -check-prefix=RV32I %s
-; RUN: llc -mtriple=riscv32 -mattr=+m -verify-machineinstrs -riscv-enable-sink-fold < %s \
+; RUN: llc -mtriple=riscv32 -mattr=+m -verify-machineinstrs < %s \
 ; RUN:   | FileCheck -check-prefix=RV32IM %s
-; RUN: llc -mtriple=riscv64 -verify-machineinstrs -riscv-enable-sink-fold < %s \
+; RUN: llc -mtriple=riscv64 -verify-machineinstrs < %s \
 ; RUN:   | FileCheck -check-prefix=RV64I %s
-; RUN: llc -mtriple=riscv64 -mattr=+m -verify-machineinstrs -riscv-enable-sink-fold < %s \
+; RUN: llc -mtriple=riscv64 -mattr=+m -verify-machineinstrs < %s \
 ; RUN:   | FileCheck -check-prefix=RV64IM %s
 
 define <4 x i16> @fold_srem_vec_1(<4 x i16> %x) nounwind {

llvm/test/CodeGen/RISCV/urem-vector-lkk.ll

@@ -1,11 +1,11 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
-; RUN: llc -mtriple=riscv32 -verify-machineinstrs -riscv-enable-sink-fold < %s \
+; RUN: llc -mtriple=riscv32 -verify-machineinstrs < %s \
 ; RUN:   | FileCheck -check-prefixes=CHECK,RV32I %s
-; RUN: llc -mtriple=riscv32 -mattr=+m -verify-machineinstrs -riscv-enable-sink-fold < %s \
+; RUN: llc -mtriple=riscv32 -mattr=+m -verify-machineinstrs < %s \
 ; RUN:   | FileCheck -check-prefixes=CHECK,RV32IM %s
-; RUN: llc -mtriple=riscv64 -verify-machineinstrs -riscv-enable-sink-fold < %s \
+; RUN: llc -mtriple=riscv64 -verify-machineinstrs < %s \
 ; RUN:   | FileCheck -check-prefixes=CHECK,RV64I %s
-; RUN: llc -mtriple=riscv64 -mattr=+m -verify-machineinstrs -riscv-enable-sink-fold < %s \
+; RUN: llc -mtriple=riscv64 -mattr=+m -verify-machineinstrs < %s \
 ; RUN:   | FileCheck -check-prefixes=CHECK,RV64IM %s