52 lines
1.8 KiB
Diff
52 lines
1.8 KiB
Diff
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From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
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From: Paolo Bonzini <pbonzini@redhat.com>
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Date: Thu, 9 May 2024 12:38:10 +0200
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Subject: [PATCH] target/i386: fix operand size for DATA16 REX.W POPCNT
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According to the manual, 32-bit vs 64-bit is governed by REX.W
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and REX ignores the 0x66 prefix. This can be confirmed with this
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program:
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#include <stdio.h>
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int main()
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{
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int x = 0x12340000;
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int y;
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asm("popcntl %1, %0" : "=r" (y) : "r" (x)); printf("%x\n", y);
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asm("mov $-1, %0; .byte 0x66; popcntl %1, %0" : "+r" (y) : "r" (x)); printf("%x\n", y);
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asm("mov $-1, %0; .byte 0x66; popcntq %q1, %q0" : "+r" (y) : "r" (x)); printf("%x\n", y);
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}
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which prints 5/ffff0000/5 on real hardware and 5/ffff0000/ffff0000
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on QEMU.
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Cc: qemu-stable@nongnu.org
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Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
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Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
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Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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(cherry picked from commit 41c685dc59bb611096f3bb6a663cfa82e4cba97b)
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[FE: keep mo_64_32 helper which still has other users in 9.0.0]
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Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
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---
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target/i386/tcg/translate.c | 7 +------
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1 file changed, 1 insertion(+), 6 deletions(-)
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diff --git a/target/i386/tcg/translate.c b/target/i386/tcg/translate.c
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index 76a42c679c..b60f3bd642 100644
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--- a/target/i386/tcg/translate.c
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+++ b/target/i386/tcg/translate.c
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@@ -6799,12 +6799,7 @@ static bool disas_insn(DisasContext *s, CPUState *cpu)
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modrm = x86_ldub_code(env, s);
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reg = ((modrm >> 3) & 7) | REX_R(s);
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- if (s->prefix & PREFIX_DATA) {
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- ot = MO_16;
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- } else {
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- ot = mo_64_32(dflag);
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- }
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-
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+ ot = dflag;
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gen_ldst_modrm(env, s, modrm, ot, OR_TMP0, 0);
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gen_extu(ot, s->T0);
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tcg_gen_mov_tl(cpu_cc_src, s->T0);
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