File 1105-jit-Simplify-float-instructions-x86.patch of Package erlang

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File 1105-jit-Simplify-float-instructions-x86.patch of Package erlang (Revision f11a8876faa0a8240b9c8df85bc35eb2)

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From dac147a8e0b1f2624a1d99f68d594d80d46d6a24 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?John=20H=C3=B6gberg?= <john@erlang.org>
Date: Thu, 22 Apr 2021 09:38:13 +0200
Subject: [PATCH 05/20] jit: Simplify float instructions (x86)

---
 erts/emulator/beam/jit/x86/beam_asm.hpp       |  10 +-
 .../emulator/beam/jit/x86/beam_asm_module.cpp |  12 --
 erts/emulator/beam/jit/x86/instr_float.cpp    | 143 ++++++++----------
 3 files changed, 72 insertions(+), 93 deletions(-)

diff --git a/erts/emulator/beam/jit/x86/beam_asm.hpp b/erts/emulator/beam/jit/x86/beam_asm.hpp
index 55a7f7f5b3..ef914c5a04 100644
--- a/erts/emulator/beam/jit/x86/beam_asm.hpp
+++ b/erts/emulator/beam/jit/x86/beam_asm.hpp
@@ -858,6 +858,7 @@ class BeamGlobalAssembler : public BeamAssembler {
     _(call_nif_shared)                                                         \
     _(call_nif_yield_helper)                                                   \
     _(catch_end_shared)                                                        \
+    _(check_float_error)                                                       \
     _(dispatch_bif)                                                            \
     _(dispatch_nif)                                                            \
     _(dispatch_return)                                                         \
@@ -867,6 +868,7 @@ class BeamGlobalAssembler : public BeamAssembler {
     _(generic_bp_global)                                                       \
     _(generic_bp_local)                                                        \
     _(debug_bp)                                                                \
+    _(fconv_shared)                                                            \
     _(handle_element_error)                                                    \
     _(handle_hd_error)                                                         \
     _(i_band_body_shared)                                                      \
@@ -1018,9 +1020,6 @@ class BeamModuleAssembler : public BeamAssembler {
     Label genericBPTramp;
     Label on_load;
 
-    Label floatMax;
-    Label floatSignMask;
-
     Eterm mod;
 
     /* Save the last PC for an error. */
@@ -1133,7 +1132,10 @@ protected:
                             const ArgVal &Fail,
                             const std::vector<ArgVal> &args);
 
-    void emit_check_float(Label next, x86::Xmm value);
+    void emit_float_instr(uint32_t instId,
+                          const ArgVal &LHS,
+                          const ArgVal &RHS,
+                          const ArgVal &Dst);
 
     void emit_is_small(Label fail, x86::Gp Reg);
     void emit_is_both_small(Label fail, x86::Gp A, x86::Gp B);
diff --git a/erts/emulator/beam/jit/x86/beam_asm_module.cpp b/erts/emulator/beam/jit/x86/beam_asm_module.cpp
index 442a8fd0f7..9ec249db69 100644
--- a/erts/emulator/beam/jit/x86/beam_asm_module.cpp
+++ b/erts/emulator/beam/jit/x86/beam_asm_module.cpp
@@ -106,18 +106,6 @@ BeamModuleAssembler::BeamModuleAssembler(BeamGlobalAssembler *ga,
     embed_zeros(sizeof(BeamCodeHeader) +
                 sizeof(ErtsCodeInfo *) * num_functions);
 
-    floatMax = a.newLabel();
-    a.align(kAlignCode, 8);
-    a.bind(floatMax);
-    a.embedDouble(DBL_MAX);
-
-    floatSignMask = a.newLabel();
-    /* This is 128-bit aligned to allow its direct use in SSE instructions,
-     * saving us from needing a separate `movupd` instruction. */
-    a.align(kAlignCode, 16);
-    a.bind(floatSignMask);
-    a.embedUInt64(0x7FFFFFFFFFFFFFFFul);
-
     /* Shared trampoline for function_clause errors, which can't jump straight
      * to `i_func_info_shared` due to size restrictions. */
     funcInfo = a.newLabel();
diff --git a/erts/emulator/beam/jit/x86/instr_float.cpp b/erts/emulator/beam/jit/x86/instr_float.cpp
index 43acf485ff..b39433164e 100644
--- a/erts/emulator/beam/jit/x86/instr_float.cpp
+++ b/erts/emulator/beam/jit/x86/instr_float.cpp
@@ -25,6 +25,50 @@ extern "C"
 #include "big.h"
 }
 
+/* Fixes a silly compilation error on Windows, where the following macro
+ * prevents us from using `std::numeric_limits<T>::max()` */
+#ifdef max
+#    undef max
+#endif
+
+void BeamGlobalAssembler::emit_check_float_error() {
+    Label error = a.newLabel(), floatMax = a.newLabel(),
+          floatSignMask = a.newLabel();
+
+    a.movsd(x86::xmm2, x86::xmm0);
+    a.movsd(x86::xmm1, x86::qword_ptr(floatMax));
+    a.andpd(x86::xmm2, x86::xmmword_ptr(floatSignMask));
+    a.ucomisd(x86::xmm1, x86::xmm2);
+    a.short_().jb(error);
+    a.ret();
+
+    a.bind(error);
+    {
+        a.mov(x86::qword_ptr(c_p, offsetof(Process, freason)),
+              imm(EXC_BADARITH));
+        a.sub(ARG4, ARG4);
+        a.jmp(labels[raise_exception]);
+    }
+
+    a.align(kAlignCode, 16);
+    a.bind(floatSignMask);
+    a.embedUInt64(0x7FFFFFFFFFFFFFFFul);
+    a.bind(floatMax);
+    a.embedDouble(std::numeric_limits<double>::max());
+}
+
+void BeamModuleAssembler::emit_float_instr(uint32_t instId,
+                                           const ArgVal &LHS,
+                                           const ArgVal &RHS,
+                                           const ArgVal &Dst) {
+    a.movsd(x86::xmm0, getArgRef(LHS));
+    a.movsd(x86::xmm1, getArgRef(RHS));
+
+    a.emit(instId, x86::xmm0, x86::xmm1);
+    safe_fragment_call(ga->get_check_float_error());
+    a.movsd(getArgRef(Dst), x86::xmm0);
+}
+
 void BeamModuleAssembler::emit_fload(const ArgVal &Src, const ArgVal &Dst) {
     /* {thing_word,double} */
     mov_arg(ARG1, Src);
@@ -47,122 +91,67 @@ void BeamModuleAssembler::emit_fstore(const ArgVal &Src, const ArgVal &Dst) {
     a.add(HTOP, imm(FLOAT_SIZE_OBJECT * sizeof(Eterm)));
 }
 
-static int handle_fconv(Eterm src, double *dst) {
+static double handle_fconv(Eterm src) {
     if (is_small(src)) {
-        *dst = (double)signed_val(src);
+        return (double)signed_val(src);
     } else if (is_float(src)) {
-        GET_DOUBLE(src, *(FloatDef *)dst);
+        double res;
+        GET_DOUBLE(src, *(FloatDef *)&res);
+        return res;
     } else if (is_big(src)) {
-        if (big_to_double(src, dst) < 0) {
-            return 1;
+        double res;
+        if (big_to_double(src, &res) < 0) {
+            return NAN;
         }
+        return res;
     } else {
-        return 1;
+        return NAN;
     }
-
-    return 0;
 }
 
-void BeamModuleAssembler::emit_fconv(const ArgVal &Src, const ArgVal &Dst) {
-    Label next = a.newLabel();
-
-    mov_arg(ARG1, Src);
-    a.lea(ARG2, getArgRef(Dst));
-
+void BeamGlobalAssembler::emit_fconv_shared() {
     emit_enter_runtime();
-
-    runtime_call<2>(handle_fconv);
-
+    runtime_call<1>(handle_fconv);
     emit_leave_runtime();
 
-    a.test(RET, RET);
-    a.short_().je(next);
-
-    emit_error(EXC_BADARITH);
-
-    a.bind(next);
+    a.jmp(labels[check_float_error]);
 }
 
-void BeamModuleAssembler::emit_check_float(Label next, x86::Xmm value) {
-    a.movsd(x86::xmm2, value);
-    a.movsd(x86::xmm1, x86::qword_ptr(floatMax));
-    a.andpd(x86::xmm2, x86::xmmword_ptr(floatSignMask));
-    a.ucomisd(x86::xmm1, x86::xmm2);
-    a.short_().jnb(next);
-
-    emit_error(EXC_BADARITH);
+void BeamModuleAssembler::emit_fconv(const ArgVal &Src, const ArgVal &Dst) {
+    mov_arg(ARG1, Src);
+    safe_fragment_call(ga->get_fconv_shared());
+    a.movsd(getArgRef(Dst), x86::xmm0);
 }
 
 void BeamModuleAssembler::emit_i_fadd(const ArgVal &LHS,
                                       const ArgVal &RHS,
                                       const ArgVal &Dst) {
-    Label next = a.newLabel();
-
-    a.movsd(x86::xmm0, getArgRef(LHS));
-    a.movsd(x86::xmm1, getArgRef(RHS));
-    a.addpd(x86::xmm0, x86::xmm1);
-
-    emit_check_float(next, x86::xmm0);
-
-    a.bind(next);
-    a.movsd(getArgRef(Dst), x86::xmm0);
+    emit_float_instr(x86::Inst::kIdAddpd, LHS, RHS, Dst);
 }
 
 void BeamModuleAssembler::emit_i_fsub(const ArgVal &LHS,
                                       const ArgVal &RHS,
                                       const ArgVal &Dst) {
-    Label next = a.newLabel();
-
-    a.movsd(x86::xmm0, getArgRef(LHS));
-    a.movsd(x86::xmm1, getArgRef(RHS));
-    a.subpd(x86::xmm0, x86::xmm1);
-
-    emit_check_float(next, x86::xmm0);
-
-    a.bind(next);
-    a.movsd(getArgRef(Dst), x86::xmm0);
+    emit_float_instr(x86::Inst::kIdSubpd, LHS, RHS, Dst);
 }
 
 void BeamModuleAssembler::emit_i_fmul(const ArgVal &LHS,
                                       const ArgVal &RHS,
                                       const ArgVal &Dst) {
-    Label next = a.newLabel();
-
-    a.movsd(x86::xmm0, getArgRef(LHS));
-    a.movsd(x86::xmm1, getArgRef(RHS));
-    a.mulpd(x86::xmm0, x86::xmm1);
-
-    emit_check_float(next, x86::xmm0);
-
-    a.bind(next);
-    a.movsd(getArgRef(Dst), x86::xmm0);
+    emit_float_instr(x86::Inst::kIdMulpd, LHS, RHS, Dst);
 }
 
 void BeamModuleAssembler::emit_i_fdiv(const ArgVal &LHS,
                                       const ArgVal &RHS,
                                       const ArgVal &Dst) {
-    Label next = a.newLabel();
-
-    a.movsd(x86::xmm0, getArgRef(LHS));
-    a.movsd(x86::xmm1, getArgRef(RHS));
-    a.divpd(x86::xmm0, x86::xmm1);
-
-    emit_check_float(next, x86::xmm0);
-
-    a.bind(next);
-    a.movsd(getArgRef(Dst), x86::xmm0);
+    emit_float_instr(x86::Inst::kIdDivpd, LHS, RHS, Dst);
 }
 
 void BeamModuleAssembler::emit_i_fnegate(const ArgVal &Src, const ArgVal &Dst) {
-    Label next = a.newLabel();
-
     /* xmm0 = 0.0 */
     a.psubd(x86::xmm0, x86::xmm0);
     a.movsd(x86::xmm1, getArgRef(Src));
     a.subpd(x86::xmm0, x86::xmm1);
-
-    emit_check_float(next, x86::xmm0);
-
-    a.bind(next);
+    safe_fragment_call(ga->get_check_float_error());
     a.movsd(getArgRef(Dst), x86::xmm0);
 }
-- 
2.26.2

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File 1105-jit-Simplify-float-instructions-x86.patch of Package erlang (Revision f11a8876faa0a8240b9c8df85bc35eb2)

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