From ad5d0d7b776bc2f6a2739ca4578ab0c932e6e33a Mon Sep 17 00:00:00 2001
From: Lioncash <mathew1800@gmail.com>
Date: Wed, 10 Feb 2021 16:20:43 -0500
Subject: [PATCH] thumb32: Implement SXTAB
---
src/frontend/A32/decoder/thumb32.inc | 2 +-
.../impl/thumb32_data_processing_register.cpp | 13 +++++++++++++
src/frontend/A32/translate/impl/translate_thumb.h | 1 +
3 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/src/frontend/A32/decoder/thumb32.inc b/src/frontend/A32/decoder/thumb32.inc
index 9da07c30..0083caee 100644
--- a/src/frontend/A32/decoder/thumb32.inc
+++ b/src/frontend/A32/decoder/thumb32.inc
@@ -204,7 +204,7 @@ INST(thumb32_SXTAB16, "SXTAB16", "111110100010nnnn1111dd
INST(thumb32_UXTB16, "UXTB16", "11111010001111111111dddd10rrmmmm")
INST(thumb32_UXTAB16, "UXTAB16", "111110100011nnnn1111dddd10rrmmmm")
INST(thumb32_SXTB, "SXTB", "11111010010011111111dddd10rrmmmm")
-//INST(thumb32_SXTAB, "SXTAB", "111110100100----1111----1-------")
+INST(thumb32_SXTAB, "SXTAB", "111110100100nnnn1111dddd10rrmmmm")
//INST(thumb32_UXTB, "UXTB", "11111010010111111111----1-------")
//INST(thumb32_UXTAB, "UXTAB", "111110100101----1111----1-------")
diff --git a/src/frontend/A32/translate/impl/thumb32_data_processing_register.cpp b/src/frontend/A32/translate/impl/thumb32_data_processing_register.cpp
index e8c4358f..86945a2d 100644
--- a/src/frontend/A32/translate/impl/thumb32_data_processing_register.cpp
+++ b/src/frontend/A32/translate/impl/thumb32_data_processing_register.cpp
@@ -37,6 +37,19 @@ bool ThumbTranslatorVisitor::thumb32_SXTB16(Reg d, SignExtendRotation rotate, Re
return true;
}
+bool ThumbTranslatorVisitor::thumb32_SXTAB(Reg n, Reg d, SignExtendRotation rotate, Reg m) {
+ if (d == Reg::PC || m == Reg::PC) {
+ return UnpredictableInstruction();
+ }
+
+ const auto rotated = Rotate(ir, m, rotate);
+ const auto reg_n = ir.GetRegister(n);
+ const auto result = ir.Add(reg_n, ir.SignExtendByteToWord(ir.LeastSignificantByte(rotated)));
+
+ ir.SetRegister(d, result);
+ return true;
+}
+
bool ThumbTranslatorVisitor::thumb32_SXTAB16(Reg n, Reg d, SignExtendRotation rotate, Reg m) {
if (d == Reg::PC || m == Reg::PC) {
return UnpredictableInstruction();
diff --git a/src/frontend/A32/translate/impl/translate_thumb.h b/src/frontend/A32/translate/impl/translate_thumb.h
index a40a07cc..db38df9b 100644
--- a/src/frontend/A32/translate/impl/translate_thumb.h
+++ b/src/frontend/A32/translate/impl/translate_thumb.h
@@ -124,6 +124,7 @@ struct ThumbTranslatorVisitor final {
// thumb32 data processing (register) instructions
bool thumb32_SXTB(Reg d, SignExtendRotation rotate, Reg m);
bool thumb32_SXTB16(Reg d, SignExtendRotation rotate, Reg m);
+ bool thumb32_SXTAB(Reg n, Reg d, SignExtendRotation rotate, Reg m);
bool thumb32_SXTAB16(Reg n, Reg d, SignExtendRotation rotate, Reg m);
bool thumb32_SXTH(Reg d, SignExtendRotation rotate, Reg m);
bool thumb32_SXTAH(Reg n, Reg d, SignExtendRotation rotate, Reg m);