[riscv] avoid cpu probing in li_ptr

kxxt · V8 LUCI CQ · commit a3cc8522a4c8 · 2024-06-11T01:10:31.000Z
CPU probing is an expensive thing to do and we should avoid doing it upon every li_ptr call. Fixes performance regresion bisected in riscv-forks/electron#1 Change-Id: Ib5ff89b2a730e08de6735123ae60adeffe811ed8 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5612950 Commit-Queue: Yahan Lu <yahan@iscas.ac.cn> Reviewed-by: Yahan Lu <yahan@iscas.ac.cn> Reviewed-by: Michael Lippautz <mlippautz@chromium.org> Cr-Commit-Position: refs/heads/main@{#94349}
diff --git a/AUTHORS b/AUTHORS
@@ -183,6 +183,7 @@ Kevin Gibbons <bakkot@gmail.com>
 Keyhan Vakil <kvakil@googlecontrib.kvakil.me>
 Kris Selden <kris.selden@gmail.com>
 Kyounga Ra <kyounga@alticast.com>
+Levi Zim <rsworktech@outlook.com>
 Loo Rong Jie <loorongjie@gmail.com>
 Lu Yahan <yahan@iscas.ac.cn>
 Ludovic Mermod <ludovic.mermod@gmail.com>
diff --git a/src/codegen/riscv/assembler-riscv.cc b/src/codegen/riscv/assembler-riscv.cc
@@ -1104,7 +1104,6 @@ void Assembler::GeneralLi(Register rd, int64_t imm) {
 }
 
 void Assembler::li_ptr(Register rd, int64_t imm) {
-  base::CPU cpu;
   // Initialize rd with an address
   // Pointers are 48 bits
   // 6 fixed instructions are generated

-Original file line number
+Diff line change
 Keyhan Vakil <[email protected]>
 Kris Selden <[email protected]>
 Kyounga Ra <[email protected]>
 +Levi Zim <[email protected]>
 Loo Rong Jie <[email protected]>
 Lu Yahan <[email protected]>
 Ludovic Mermod <[email protected]>
Original file line number	Diff line number	Diff line change
`@@ -1104,7 +1104,6 @@ void Assembler::GeneralLi(Register rd, int64_t imm) {`
`1104`	`1104`	`}`
`1105`	`1105`
`1106`	`1106`	`void Assembler::li_ptr(Register rd, int64_t imm) {`
`1107`		`- base::CPU cpu;`
`1108`	`1107`	`// Initialize rd with an address`
`1109`	`1108`	`// Pointers are 48 bits`
`1110`	`1109`	`// 6 fixed instructions are generated`