[PATCH 6/6] host/i386: assume presence of POPCNT

Paolo Bonzini posted 6 patches 5 months, 3 weeks ago
Maintainers: Richard Henderson <richard.henderson@linaro.org>, Paolo Bonzini <pbonzini@redhat.com>, "Marc-André Lureau" <marcandre.lureau@redhat.com>, "Daniel P. Berrangé" <berrange@redhat.com>, Thomas Huth <thuth@redhat.com>, "Philippe Mathieu-Daudé" <philmd@linaro.org>
[PATCH 6/6] host/i386: assume presence of POPCNT
Posted by Paolo Bonzini 5 months, 3 weeks ago
QEMU now requires an x86-64-v2 host, which has the POPCNT instruction.
Use it freely in TCG-generated code.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 host/include/i386/host/cpuinfo.h | 1 -
 tcg/i386/tcg-target.h            | 5 ++---
 util/cpuinfo-i386.c              | 1 -
 3 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/host/include/i386/host/cpuinfo.h b/host/include/i386/host/cpuinfo.h
index 72f6fad61e5..c1e94d75ce1 100644
--- a/host/include/i386/host/cpuinfo.h
+++ b/host/include/i386/host/cpuinfo.h
@@ -11,7 +11,6 @@
 #define CPUINFO_ALWAYS          (1u << 0)  /* so cpuinfo is nonzero */
 #define CPUINFO_MOVBE           (1u << 2)
 #define CPUINFO_LZCNT           (1u << 3)
-#define CPUINFO_POPCNT          (1u << 4)
 #define CPUINFO_BMI1            (1u << 5)
 #define CPUINFO_BMI2            (1u << 6)
 #define CPUINFO_AVX1            (1u << 9)
diff --git a/tcg/i386/tcg-target.h b/tcg/i386/tcg-target.h
index 2f67a97e059..ecc69827287 100644
--- a/tcg/i386/tcg-target.h
+++ b/tcg/i386/tcg-target.h
@@ -111,7 +111,6 @@ typedef enum {
 #endif
 
 #define have_bmi1         (cpuinfo & CPUINFO_BMI1)
-#define have_popcnt       (cpuinfo & CPUINFO_POPCNT)
 #define have_avx1         (cpuinfo & CPUINFO_AVX1)
 #define have_avx2         (cpuinfo & CPUINFO_AVX2)
 #define have_movbe        (cpuinfo & CPUINFO_MOVBE)
@@ -143,7 +142,7 @@ typedef enum {
 #define TCG_TARGET_HAS_nor_i32          0
 #define TCG_TARGET_HAS_clz_i32          1
 #define TCG_TARGET_HAS_ctz_i32          1
-#define TCG_TARGET_HAS_ctpop_i32        have_popcnt
+#define TCG_TARGET_HAS_ctpop_i32        1
 #define TCG_TARGET_HAS_deposit_i32      1
 #define TCG_TARGET_HAS_extract_i32      1
 #define TCG_TARGET_HAS_sextract_i32     1
@@ -178,7 +177,7 @@ typedef enum {
 #define TCG_TARGET_HAS_nor_i64          0
 #define TCG_TARGET_HAS_clz_i64          1
 #define TCG_TARGET_HAS_ctz_i64          1
-#define TCG_TARGET_HAS_ctpop_i64        have_popcnt
+#define TCG_TARGET_HAS_ctpop_i64        1
 #define TCG_TARGET_HAS_deposit_i64      1
 #define TCG_TARGET_HAS_extract_i64      1
 #define TCG_TARGET_HAS_sextract_i64     0
diff --git a/util/cpuinfo-i386.c b/util/cpuinfo-i386.c
index b413075b9f2..883dfa4dd95 100644
--- a/util/cpuinfo-i386.c
+++ b/util/cpuinfo-i386.c
@@ -35,7 +35,6 @@ unsigned __attribute__((constructor)) cpuinfo_init(void)
         __cpuid(1, a, b, c, d);
 
         info |= (c & bit_MOVBE ? CPUINFO_MOVBE : 0);
-        info |= (c & bit_POPCNT ? CPUINFO_POPCNT : 0);
         info |= (c & bit_PCLMUL ? CPUINFO_PCLMUL : 0);
 
         /* NOTE: our AES support requires SSSE3 (PSHUFB) as well. */
-- 
2.45.1
Re: [PATCH 6/6] host/i386: assume presence of POPCNT
Posted by Zhao Liu 5 months, 3 weeks ago
On Fri, May 31, 2024 at 11:14:57AM +0200, Paolo Bonzini wrote:
> Date: Fri, 31 May 2024 11:14:57 +0200
> From: Paolo Bonzini <pbonzini@redhat.com>
> Subject: [PATCH 6/6] host/i386: assume presence of POPCNT
> X-Mailer: git-send-email 2.45.1
> 
> QEMU now requires an x86-64-v2 host, which has the POPCNT instruction.
> Use it freely in TCG-generated code.
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  host/include/i386/host/cpuinfo.h | 1 -
>  tcg/i386/tcg-target.h            | 5 ++---
>  util/cpuinfo-i386.c              | 1 -
>  3 files changed, 2 insertions(+), 5 deletions(-)

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>