From fb483f1950b8a07a5ea38dbd3e21ad981ffd51ea Mon Sep 17 00:00:00 2001 From: Andreas Kling Date: Thu, 26 Oct 2023 15:29:42 +0200 Subject: [PATCH] LibJIT: Emit 8-bit displacement variants for mov when possible --- Userland/Libraries/LibJIT/Assembler.h | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/Userland/Libraries/LibJIT/Assembler.h b/Userland/Libraries/LibJIT/Assembler.h index 29f4ceaaf0c..df8fe3c386a 100644 --- a/Userland/Libraries/LibJIT/Assembler.h +++ b/Userland/Libraries/LibJIT/Assembler.h @@ -140,8 +140,13 @@ struct Assembler { | ((to_underlying(src.reg) >= 8) ? 1 << 2 : 0) | ((to_underlying(dst.reg) >= 8) ? 1 << 0 : 0)); emit8(0x89); - emit8(0x80 | (encode_reg(src.reg) << 3) | encode_reg(dst.reg)); - emit32(dst.offset_or_immediate); + if (dst.offset_or_immediate <= 127) { + emit8(0x40 | (encode_reg(src.reg) << 3) | encode_reg(dst.reg)); + emit8(dst.offset_or_immediate); + } else { + emit8(0x80 | (encode_reg(src.reg) << 3) | encode_reg(dst.reg)); + emit32(dst.offset_or_immediate); + } return; } @@ -150,8 +155,13 @@ struct Assembler { | ((to_underlying(dst.reg) >= 8) ? 1 << 2 : 0) | ((to_underlying(src.reg) >= 8) ? 1 << 0 : 0)); emit8(0x8b); - emit8(0x80 | (encode_reg(dst.reg) << 3) | encode_reg(src.reg)); - emit32(src.offset_or_immediate); + if (src.offset_or_immediate <= 127) { + emit8(0x40 | (encode_reg(dst.reg) << 3) | encode_reg(src.reg)); + emit8(src.offset_or_immediate); + } else { + emit8(0x80 | (encode_reg(dst.reg) << 3) | encode_reg(src.reg)); + emit32(src.offset_or_immediate); + } return; }