From 5697bf26a86c34bfad8f4b9f454813b105842d2c Mon Sep 17 00:00:00 2001
From: Nicholas Mosier <nmosier@stanford.edu>
Date: Thu, 21 Sep 2023 04:29:05 +0000
Subject: [PATCH] arch-x86: make popx87 micro-op actually pop st(0)

The popx87 micro-op did not in fact pop the st(0) floating-point
register off the stack; it acted as a no-op. This patch fixes the bug
by passing the spm=1 argument to PopX87's superclass to indicate the
floating-point stack pointer should be incremented.

GitHub issue: https://github.com/gem5/gem5/issues/344

Change-Id: I6e731882b6bcf8f0e06ebd2f66f673bf9da80717
---
 src/arch/x86/isa/microops/fpop.isa | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/arch/x86/isa/microops/fpop.isa b/src/arch/x86/isa/microops/fpop.isa
index 5365c587ec..b0b925f679 100644
--- a/src/arch/x86/isa/microops/fpop.isa
+++ b/src/arch/x86/isa/microops/fpop.isa
@@ -430,4 +430,6 @@ let {{
     class Pop87(Fp0Op):
         code = ''
         op_class = 'IntAluOp'
+        def __init__(self):
+            super().__init__(spm=1)
 }};