From 5cbcd59cf0e4ef63efdc63903d38e3d50bf2c384 Mon Sep 17 00:00:00 2001
From: Jakob Stoklund Olesen <jolesen@mozilla.com>
Date: Wed, 12 Jul 2017 16:05:20 -0700
Subject: [PATCH] Add some ISA predicates for Intel CPUID features.

Guard the popcnt instruction on the proper CPUID bits.
---
 cranelift/filetests/isa/intel/binary32.cton |  2 +-
 cranelift/filetests/isa/intel/binary64.cton |  2 +-
 cranelift/filetests/wasm/i32-arith.cton     |  4 +--
 lib/cretonne/meta/isa/intel/encodings.py    | 10 ++++---
 lib/cretonne/meta/isa/intel/settings.py     | 32 ++++++++++++++++++++-
 5 files changed, 41 insertions(+), 9 deletions(-)

diff --git a/cranelift/filetests/isa/intel/binary32.cton b/cranelift/filetests/isa/intel/binary32.cton
index 77e53ceeec..33df4794b3 100644
--- a/cranelift/filetests/isa/intel/binary32.cton
+++ b/cranelift/filetests/isa/intel/binary32.cton
@@ -1,6 +1,6 @@
 ; binary emission of 32-bit code.
 test binemit
-isa intel
+isa intel has_sse42 has_popcnt
 
 ; The binary encodings can be verified with the command:
 ;
diff --git a/cranelift/filetests/isa/intel/binary64.cton b/cranelift/filetests/isa/intel/binary64.cton
index da350d1e45..908b42ac0e 100644
--- a/cranelift/filetests/isa/intel/binary64.cton
+++ b/cranelift/filetests/isa/intel/binary64.cton
@@ -1,7 +1,7 @@
 ; binary emission of 64-bit code.
 test binemit
 set is_64bit
-isa intel
+isa intel has_sse42 has_popcnt
 
 ; The binary encodings can be verified with the command:
 ;
diff --git a/cranelift/filetests/wasm/i32-arith.cton b/cranelift/filetests/wasm/i32-arith.cton
index fc730cbe23..2992dcf5b8 100644
--- a/cranelift/filetests/wasm/i32-arith.cton
+++ b/cranelift/filetests/wasm/i32-arith.cton
@@ -2,10 +2,10 @@
 test compile
 
 set is_64bit=0
-isa intel
+isa intel has_sse42 has_popcnt
 
 set is_64bit=1
-isa intel
+isa intel has_sse42 has_popcnt
 
 ; Constants.
 
diff --git a/lib/cretonne/meta/isa/intel/encodings.py b/lib/cretonne/meta/isa/intel/encodings.py
index d8dfe53140..dc54819a8b 100644
--- a/lib/cretonne/meta/isa/intel/encodings.py
+++ b/lib/cretonne/meta/isa/intel/encodings.py
@@ -7,6 +7,7 @@ from base import instructions as base
 from base.formats import UnaryImm
 from .defs import I32, I64
 from . import recipes as r
+from . import settings as cfg
 
 for inst,           opc in [
         (base.iadd, 0x01),
@@ -81,10 +82,11 @@ for inst,           rrr in [
     I64.enc(inst.i32.i32, *r.rc(0xd3, rrr=rrr))
 
 # Population count.
-I32.enc(base.popcnt.i32, *r.urm(0xf3, 0x0f, 0xb8))
-I64.enc(base.popcnt.i64, *r.urm.rex(0xf3, 0x0f, 0xb8, w=1))
-I64.enc(base.popcnt.i32, *r.urm.rex(0xf3, 0x0f, 0xb8))
-I64.enc(base.popcnt.i32, *r.urm(0xf3, 0x0f, 0xb8))
+I32.enc(base.popcnt.i32, *r.urm(0xf3, 0x0f, 0xb8), isap=cfg.use_popcnt)
+I64.enc(base.popcnt.i64, *r.urm.rex(0xf3, 0x0f, 0xb8, w=1),
+        isap=cfg.use_popcnt)
+I64.enc(base.popcnt.i32, *r.urm.rex(0xf3, 0x0f, 0xb8), isap=cfg.use_popcnt)
+I64.enc(base.popcnt.i32, *r.urm(0xf3, 0x0f, 0xb8), isap=cfg.use_popcnt)
 
 # Loads and stores.
 I32.enc(base.store.i32.i32, *r.st(0x89))
diff --git a/lib/cretonne/meta/isa/intel/settings.py b/lib/cretonne/meta/isa/intel/settings.py
index 42e1a0ab99..9251f73c5d 100644
--- a/lib/cretonne/meta/isa/intel/settings.py
+++ b/lib/cretonne/meta/isa/intel/settings.py
@@ -2,10 +2,40 @@
 Intel settings.
 """
 from __future__ import absolute_import
-from cdsl.settings import SettingGroup
+from cdsl.settings import SettingGroup, BoolSetting
+from cdsl.predicates import And
 import base.settings as shared
 from .defs import ISA
 
 ISA.settings = SettingGroup('intel', parent=shared.group)
 
+# The has_* settings here correspond to CPUID bits.
+
+# CPUID.01H:EDX
+has_sse2 = BoolSetting("SSE2: CPUID.01H:EDX.SSE2[bit 26]")
+
+# CPUID.01H:ECX
+has_sse3 = BoolSetting("SSE3: CPUID.01H:ECX.SSE3[bit 0]")
+has_ssse3 = BoolSetting("SSSE3: CPUID.01H:ECX.SSSE3[bit 9]")
+has_sse41 = BoolSetting("SSE4.1: CPUID.01H:ECX.SSE4_1[bit 19]")
+has_sse42 = BoolSetting("SSE4.2: CPUID.01H:ECX.SSE4_2[bit 20]")
+has_popcnt = BoolSetting("POPCNT: CPUID.01H:ECX.POPCNT[bit 23]")
+has_avx = BoolSetting("AVX: CPUID.01H:ECX.AVX[bit 28]")
+
+# CPUID.(EAX=07H, ECX=0H):EBX
+has_bmi1 = BoolSetting("BMI1: CPUID.(EAX=07H, ECX=0H):EBX.BMI1[bit 3]")
+has_bmi2 = BoolSetting("BMI2: CPUID.(EAX=07H, ECX=0H):EBX.BMI2[bit 8]")
+
+# CPUID.EAX=80000001H:ECX
+has_lzcnt = BoolSetting("LZCNT: CPUID.EAX=80000001H:ECX.LZCNT[bit 5]")
+
+
+# The use_* settings here are used to determine if a feature can be used.
+
+use_sse41 = And(has_sse41)
+use_sse42 = And(has_sse42, use_sse41)
+use_popcnt = And(has_popcnt, has_sse42)
+use_bmi1 = And(has_bmi1)
+use_lzcnt = And(has_lzcnt)
+
 ISA.settings.close(globals())