cbe: changes to get zig2.c compiling under msvc

- Add cpuid / getXCR0 functions for the cbe to use instead of asm blocks
- Don't cast between 128 bit types during truncation
- Fixup truncation to use functions for shifts / adds
- Fixup float casts for undefined values
- Add test for 128 bit integer truncation

4 files changed, 107 insertions, 32 deletions

diff --git a/lib/std/zig/system/x86.zig b/lib/std/zig/system/x86.zig
index 66468ba6ff..da09983ac7 100644
--- a/lib/std/zig/system/x86.zig
+++ b/lib/std/zig/system/x86.zig
@@ -1,4 +1,5 @@
 const std = @import("std");
+const builtin = @import("builtin");
 const Target = std.Target;
 const CrossTarget = std.zig.CrossTarget;
 
@@ -527,25 +528,39 @@ const CpuidLeaf = packed struct {
     edx: u32,
 };
 
+extern fn zig_cpuid(leaf_id: u32, subid: u32, eax: *u32, ebx: *u32, ecx: *u32, edx: *u32) void;
+
 fn cpuid(leaf_id: u32, subid: u32) CpuidLeaf {
     // valid for both x86 and x86_64
     var eax: u32 = undefined;
     var ebx: u32 = undefined;
     var ecx: u32 = undefined;
     var edx: u32 = undefined;
-    asm volatile ("cpuid"
-        : [_] "={eax}" (eax),
-          [_] "={ebx}" (ebx),
-          [_] "={ecx}" (ecx),
-          [_] "={edx}" (edx),
-        : [_] "{eax}" (leaf_id),
-          [_] "{ecx}" (subid),
-    );
+
+    if (builtin.zig_backend == .stage2_c) {
+        zig_cpuid(leaf_id, subid, &eax, &ebx, &ecx, &edx);
+    } else {
+        asm volatile ("cpuid"
+            : [_] "={eax}" (eax),
+              [_] "={ebx}" (ebx),
+              [_] "={ecx}" (ecx),
+              [_] "={edx}" (edx),
+            : [_] "{eax}" (leaf_id),
+              [_] "{ecx}" (subid),
+        );
+    }
+
     return .{ .eax = eax, .ebx = ebx, .ecx = ecx, .edx = edx };
 }
 
+extern fn zig_get_xcr0() u32;
+
 // Read control register 0 (XCR0). Used to detect features such as AVX.
 fn getXCR0() u32 {
+    if (builtin.zig_backend == .stage2_c) {
+        return zig_get_xcr0();
+    }
+
     return asm volatile (
         \\ xor %%ecx, %%ecx
         \\ xgetbv
diff --git a/lib/zig.h b/lib/zig.h
index 4455316bc3..0bd526b436 100644
--- a/lib/zig.h
+++ b/lib/zig.h
@@ -6,6 +6,12 @@
 #include <stddef.h>
 #include <stdint.h>
 
+#if _MSC_VER
+#include <intrin.h>
+#else
+#include <cpuid.h>
+#endif
+
 #if !defined(__cplusplus) && __STDC_VERSION__ <= 201710L
 #if __STDC_VERSION__ >= 199901L
 #include <stdbool.h>
@@ -188,7 +194,6 @@ typedef char bool;
 #define    zig_atomic_load(obj,      order, type) __atomic_load_n    (obj,      order)
 #define zig_fence(order) __atomic_thread_fence(order)
 #elif _MSC_VER && (_M_IX86 || _M_X64)
-#include <intrin.h>
 #define memory_order_relaxed 0
 #define memory_order_consume 1
 #define memory_order_acquire 2
@@ -1367,6 +1372,11 @@ static inline zig_i128 zig_sub_i128(zig_i128 lhs, zig_i128 rhs) {
     return res;
 }
 
+zig_extern zig_i128 __multi3(zig_i128 lhs, zig_i128 rhs);
+static zig_i128 zig_mul_i128(zig_i128 lhs, zig_i128 rhs) {
+    return __multi3(lhs, rhs);
+}
+
 zig_extern zig_u128 __udivti3(zig_u128 lhs, zig_u128 rhs);
 static zig_u128 zig_div_trunc_u128(zig_u128 lhs, zig_u128 rhs) {
     return __udivti3(lhs, rhs);
@@ -1392,6 +1402,10 @@ static inline zig_i128 zig_mod_i128(zig_i128 lhs, zig_i128 rhs) {
     return zig_add_i128(rem, (((lhs.hi ^ rhs.hi) & rem.hi) < zig_as_i64(0) ? rhs : zig_as_i128(0, 0)));
 }
 
+static inline zig_i128 zig_div_floor_i128(zig_i128 lhs, zig_i128 rhs) {
+    return zig_sub_i128(zig_div_trunc_i128(lhs, rhs), zig_as_i128(0, zig_cmp_i128(zig_and_i128(zig_xor_i128(lhs, rhs), zig_rem_i128(lhs, rhs)), zig_as_i128(0, 0)) < zig_as_i32(0)));
+}
+
 #endif /* zig_has_int128 */
 
 #define zig_div_floor_u128 zig_div_trunc_u128
@@ -1465,11 +1479,6 @@ static zig_u128 zig_mul_u128(zig_u128 lhs, zig_u128 rhs) {
 static zig_u128 zig_mul_u128(zig_u128 lhs, zig_u128 rhs); // TODO
 #endif
 
-zig_extern zig_i128 __multi3(zig_i128 lhs, zig_i128 rhs);
-static zig_i128 zig_mul_i128(zig_i128 lhs, zig_i128 rhs) {
-    return __multi3(lhs, rhs);
-}
-
 static inline zig_u128 zig_mulw_u128(zig_u128 lhs, zig_u128 rhs, zig_u8 bits) {
     return zig_wrap_u128(zig_mul_u128(lhs, rhs), bits);
 }
@@ -2118,7 +2127,6 @@ zig_float_builtins(f128)
 zig_float_builtins(c_longdouble)
 
 #if _MSC_VER && (_M_IX86 || _M_X64)
-#include <intrin.h>
 
 // TODO: zig_msvc_atomic_load should load 32 bit without interlocked on x86, and load 64 bit without interlocked on x64
 
@@ -2338,3 +2346,29 @@ zig_msvc_atomics_128op(u128, min)
 zig_msvc_atomics_128op(u128, max)
 
 #endif
+
+/* ========================= Special Case Intrinsics ========================= */
+
+static inline void zig_cpuid(zig_u32 leaf_id, zig_u32 subid, zig_u32* eax, zig_u32* ebx, zig_u32* ecx, zig_u32* edx) {
+#if _MSC_VER
+    zig_u32 cpu_info[4];
+    __cpuidex(cpu_info, leaf_id, subid);
+    *eax = cpu_info[0];
+    *ebx = cpu_info[1];
+    *ecx = cpu_info[2];
+    *edx = cpu_info[3];
+#else
+    __cpuid_count(leaf_id, subid, eax, ebx, ecx, edx);
+#endif
+}
+
+static inline zig_u32 zig_get_xcr0() {
+#if _MSC_VER
+    return (zig_u32)_xgetbv(0);
+#else
+    zig_u32 eax;
+    zig_u32 edx;
+    __asm__("xgetbv" : "=a"(eax), "=d"(edx) : "c"(0));
+    return eax;
+#endif
+}
diff --git a/src/codegen/c.zig b/src/codegen/c.zig
index 216366e576..b97626990d 100644
--- a/src/codegen/c.zig
+++ b/src/codegen/c.zig
@@ -746,9 +746,9 @@ pub const DeclGen = struct {
                     var int_pl = Type.Payload.Bits{ .base = .{ .tag = .int_signed }, .data = bits };
                     const int_ty = Type.initPayload(&int_pl.base);
 
-                    try writer.writeByte('(');
-                    try dg.renderTypecast(writer, ty);
-                    try writer.writeAll(")zig_as_");
+                    try writer.writeAll("zig_cast_");
+                    try dg.renderTypeForBuiltinFnName(writer, ty);
+                    try writer.writeAll(" zig_as_");
                     try dg.renderTypeForBuiltinFnName(writer, ty);
                     try writer.writeByte('(');
                     switch (bits) {
@@ -3616,16 +3616,14 @@ fn airTrunc(f: *Function, inst: Air.Inst.Index) !CValue {
     try writer.writeAll(" = ");
 
     const needs_lo = operand_int_info.bits > 64 and dest_bits <= 64;
-    if (!needs_lo or dest_c_bits != 64 or dest_int_info.signedness != operand_int_info.signedness) {
-        try writer.writeByte('(');
-        try f.renderTypecast(writer, inst_ty);
-        try writer.writeByte(')');
-    }
-
     if (needs_lo) {
         try writer.writeAll("zig_lo_");
         try f.object.dg.renderTypeForBuiltinFnName(writer, operand_ty);
         try writer.writeByte('(');
+    } else if (dest_c_bits <= 64) {
+        try writer.writeByte('(');
+        try f.renderTypecast(writer, inst_ty);
+        try writer.writeByte(')');
     }
 
     if (dest_bits >= 8 and std.math.isPowerOfTwo(dest_bits)) {
@@ -3640,11 +3638,11 @@ fn airTrunc(f: *Function, inst: Air.Inst.Index) !CValue {
                 std.heap.stackFallback(@sizeOf(ExpectedContents), arena.allocator());
 
             const mask_val = try inst_ty.maxInt(stack.get(), target);
-
-            // TODO: This needs to use _and_ to do this to support > 64 bits and !zig_has_int128
+            try writer.writeAll("zig_and_");
+            try f.object.dg.renderTypeForBuiltinFnName(writer, operand_ty);
             try writer.writeByte('(');
-            try f.writeCValue(writer, operand, .Other);
-            try writer.print(" & {x})", .{try f.fmtIntLiteral(inst_ty, mask_val)});
+            try f.writeCValue(writer, operand, .FunctionArgument);
+            try writer.print(", {x})", .{try f.fmtIntLiteral(operand_ty, mask_val)});
         },
         .signed => {
             const c_bits = toCIntBits(operand_int_info.bits) orelse
@@ -3655,10 +3653,24 @@ fn airTrunc(f: *Function, inst: Air.Inst.Index) !CValue {
             };
             const shift_val = Value.initPayload(&shift_pl.base);
 
-            // TODO: This needs to use shl and shr to do this to support > 64 bits and !zig_has_int128
-            try writer.print("((int{d}_t)((uint{0d}_t)", .{c_bits});
-            try f.writeCValue(writer, operand, .Other);
-            try writer.print(" << {}) >> {0})", .{try f.fmtIntLiteral(Type.u8, shift_val)});
+            try writer.writeAll("zig_shr_");
+            try f.object.dg.renderTypeForBuiltinFnName(writer, operand_ty);
+            if (c_bits == 128) {
+                try writer.print("(zig_bitcast_i{d}(", .{c_bits});
+            } else {
+                try writer.print("((int{d}_t)", .{c_bits});
+            }
+            try writer.print("zig_shl_u{d}(", .{c_bits});
+            if (c_bits == 128) {
+                try writer.print("zig_bitcast_u{d}(", .{c_bits});
+            } else {
+                try writer.print("(uint{d}_t)", .{c_bits});
+            }
+            try f.writeCValue(writer, operand, .FunctionArgument);
+            if (c_bits == 128) try writer.writeByte(')');
+            try writer.print(", {})", .{ try f.fmtIntLiteral(Type.u8, shift_val) });
+            if (c_bits == 128) try writer.writeByte(')');
+            try writer.print(", {})", .{ try f.fmtIntLiteral(Type.u8, shift_val) });
         },
     }
 
diff --git a/test/behavior/basic.zig b/test/behavior/basic.zig
index 6fcef06fc1..e704e190f3 100644
--- a/test/behavior/basic.zig
+++ b/test/behavior/basic.zig
@@ -37,6 +37,20 @@ test "truncate to non-power-of-two integers" {
     try testTrunc(i32, i5, std.math.maxInt(i32), -1);
 }
 
+test "truncate to non-power-of-two integers from 128-bit" {
+    if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
+
+    try testTrunc(u128, u1, 0xffffffff_ffffffff_ffffffff_01010101, 0x01);
+    try testTrunc(u128, u1, 0xffffffff_ffffffff_ffffffff_01010110, 0x00);
+    try testTrunc(u128, u2, 0xffffffff_ffffffff_ffffffff_01010101, 0x01);
+    try testTrunc(u128, u2, 0xffffffff_ffffffff_ffffffff_01010102, 0x02);
+    try testTrunc(i128, i5, -4, -4);
+    try testTrunc(i128, i5, 4, 4);
+    try testTrunc(i128, i5, -28, 4);
+    try testTrunc(i128, i5, 28, -4);
+    try testTrunc(i128, i5, std.math.maxInt(i128), -1);
+}
+
 fn testTrunc(comptime Big: type, comptime Little: type, big: Big, little: Little) !void {
     try expect(@truncate(Little, big) == little);
 }