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gasm-sdk/asm/riscv_encode_test.go
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// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
// SPDX-License-Identifier: BSD-3-Clause
package asm
import (
"testing"
"sourcedock.dev/petrbalvin/gasm-devkit/ast"
"sourcedock.dev/petrbalvin/gasm-devkit/parser"
)
// firstTextRISCV parses assembly source and returns the first TEXT function body.
func firstTextRISCV(t *testing.T, src string) *ast.Text {
t.Helper()
f, errs := parser.Parse("f_riscv64.s", src)
if len(errs) > 0 {
t.Fatalf("parse: %v", errs)
}
for _, d := range f.Decls {
if fn, ok := d.(*ast.Text); ok {
return fn
}
}
t.Fatal("no TEXT found")
return nil
}
// assembleRISCVHelper assembles one TEXT function and returns its code bytes.
func assembleRISCVHelper(t *testing.T, fn *ast.Text) []byte {
t.Helper()
code, _, _, err := assembleRISCV(fn)
if err != nil {
t.Fatalf("assemble: %v", err)
}
return code
}
func TestRISCV_add(t *testing.T) {
// func add(a, b int64) int64
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·add(SB), NOSPLIT, $0-24
MOV a+0(FP), X10
MOV b+8(FP), X11
ADD X11, X10, X10
MOV X10, ret+16(FP)
RET
`)
code := assembleRISCVHelper(t, fn)
// should be 12 bytes with RVC: C.LDSP + C.LDSP + ADD + C.SDSP + C.JR
_ = code
if len(code) == 0 {
t.Error("empty output")
}
}
func TestRISCV_arithmetic(t *testing.T) {
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·arith(SB), NOSPLIT, $0
ADD X10, X11, X12
SUB X12, X13, X14
MUL X14, X15, X16
DIV X16, X17, X18
REM X18, X19, X20
RET
`)
code := assembleRISCVHelper(t, fn)
// 5 R-type instructions + RET compressed = 5*4 + 2 = 22
if len(code) != 22 {
t.Errorf("expected 22 bytes, got %d", len(code))
}
}
func TestRISCV_loadStore(t *testing.T) {
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·mem(SB), NOSPLIT, $0
LD (X10), X11
SD X11, (X12)
LW (X13), X14
SW X14, (X15)
RET
`)
code := assembleRISCVHelper(t, fn)
// 4 loads/stores (4B each) + C.JR RET (2B) = 18
if len(code) != 18 {
t.Errorf("expected 18 bytes, got %d", len(code))
}
}
func TestRISCV_immediate(t *testing.T) {
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·imm(SB), NOSPLIT, $0
ADDI X10, $42, X11
ANDI X11, $0xFF, X12
ORI X12, $1, X13
XORI X13, $0, X14
RET
`)
code := assembleRISCVHelper(t, fn)
// 4 I-type + C.JR = 4*4 + 2 = 18
if len(code) != 18 {
t.Errorf("expected 18 bytes, got %d", len(code))
}
}
func TestRISCV_branches(t *testing.T) {
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·br(SB), NOSPLIT, $0
ADDI X10, $1, X10
loop:
BEQ X10, X11, done
ADDI X10, $1, X10
JMP loop
done:
RET
`)
code := assembleRISCVHelper(t, fn)
_ = code
if len(code) == 0 {
t.Error("empty output")
}
}
func TestRISCV_MOV_imm_small(t *testing.T) {
// MOV $42, rd → ADDI (fits in 12 bits). Not RVC-compressed (treated as MOV, not ADDI).
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·small(SB), NOSPLIT, $0
MOV $42, X10
RET
`)
code := assembleRISCVHelper(t, fn)
// ADDI (4B) + C.JR (2B) = 6
if len(code) != 6 {
t.Errorf("expected 6 bytes, got %d", len(code))
}
}
func TestRISCV_MOV_imm_large(t *testing.T) {
// MOV $0x12345, rd → LUI + ADDIW (8 bytes total)
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·large(SB), NOSPLIT, $0
MOV $0x12345, X10
RET
`)
code := assembleRISCVHelper(t, fn)
// LUI (4B) + ADDIW (4B) + C.JR (2B) = 10
if len(code) != 10 {
t.Errorf("expected 10 bytes, got %d", len(code))
}
}
func TestRISCV_MOV_reg(t *testing.T) {
// MOV rs, rd → ADDI $0, rs, rd, compresses to C.MV
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·reg(SB), NOSPLIT, $0
MOV X10, X11
RET
`)
code := assembleRISCVHelper(t, fn)
// C.MV (2B) + C.JR (2B) = 4
if len(code) != 4 {
t.Errorf("expected 4 bytes, got %d (% x)", len(code), code)
}
}
func TestRISCV_MOV_frame(t *testing.T) {
// MOV name+off(FP), rd → load with frame mapping
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·frame(SB), NOSPLIT, $0-8
MOV a+0(FP), X10
MOV X10, ret+0(FP)
RET
`)
code := assembleRISCVHelper(t, fn)
// C.LDSP (2B) + C.SDSP (2B) + C.JR (2B) = 6
if len(code) != 6 {
t.Errorf("expected 6 bytes, got %d", len(code))
}
}
func TestRISCV_RVC_loadStore(t *testing.T) {
// Verify that loads/stores from SP are compressed.
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·rvcstore(SB), NOSPLIT, $0
LD 0(SP), X10
SD X10, 8(SP)
RET
`)
code := assembleRISCVHelper(t, fn)
// C.LDSP (2B) + C.SDSP (2B) + C.JR (2B) = 6
if len(code) != 6 {
t.Errorf("expected 6 bytes, got %d (% x)", len(code), code)
}
}
func TestRISCV_atomics(t *testing.T) {
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·amo(SB), NOSPLIT, $0
AMOADDD X10, (X11), X12
LRD (X13), X14
SCD X15, (X16), X17
RET
`)
code := assembleRISCVHelper(t, fn)
// 3 AMO instructions (4B each) + C.JR (2B) = 14
if len(code) != 14 {
t.Errorf("expected 14 bytes, got %d", len(code))
}
}
func TestRISCV_fpArith(t *testing.T) {
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·fpadd(SB), NOSPLIT, $0
FADDD F10, F11, F12
FSUBD F12, F13, F14
FMULD F14, F15, F16
FDIVD F16, F17, F18
FSQRTD F18, F19
RET
`)
code := assembleRISCVHelper(t, fn)
// 5 FP instructions (4B each) + C.JR (2B) = 22
if len(code) != 22 {
t.Errorf("expected 22 bytes, got %d (%d)", len(code), len(code))
}
}
func TestRISCV_csr(t *testing.T) {
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·csrtest(SB), NOSPLIT, $0
CSRRS $0x300, X0, X10
CSRRW $0x305, X10, X11
CSRRSI $0x304, $5, X12
RET
`)
code := assembleRISCVHelper(t, fn)
// 3 CSR instructions (4B each) + C.JR (2B) = 14
if len(code) != 14 {
t.Errorf("expected 14 bytes, got %d", len(code))
}
}
func TestRISCV_fma(t *testing.T) {
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·fmatest(SB), NOSPLIT, $0
FMADDD F10, F11, F12, F13
FMSUBD F13, F14, F15, F16
FNMSUBD F16, F17, F18, F19
FNMADDD F19, F10, F11, F12
RET
`)
code := assembleRISCVHelper(t, fn)
// 4 FMA instructions (4B each) + C.JR (2B) = 18
if len(code) != 18 {
t.Errorf("expected 18 bytes, got %d", len(code))
}
}
func TestRISCV_conversions(t *testing.T) {
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·cvt(SB), NOSPLIT, $0
FCVTDL X10, F10
FCVTLD F10, X11
FMVXD F10, X12
FMVDX X12, F11
RET
`)
code := assembleRISCVHelper(t, fn)
// 4 conversion instructions (4B each) + C.JR (2B) = 18
if len(code) != 18 {
t.Errorf("expected 18 bytes, got %d", len(code))
}
}
func TestRISCV_fpCmp(t *testing.T) {
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·cmp(SB), NOSPLIT, $0
FEQD F10, F11, X10
FLTD F12, F13, X11
FLED F14, F15, X12
RET
`)
code := assembleRISCVHelper(t, fn)
// 3 FP compare (4B each) + C.JR (2B) = 14
if len(code) != 14 {
t.Errorf("expected 14 bytes, got %d", len(code))
}
}
func TestRISCV_forwardBranch(t *testing.T) {
// Forward label reference — must not fail.
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·fwd(SB), NOSPLIT, $0
ADDI X10, $1, X10
BEQ X10, X11, done
ADDI X10, $1, X10
done:
RET
`)
code := assembleRISCVHelper(t, fn)
_ = code
if len(code) == 0 {
t.Error("empty output")
}
}
func TestRISCV_RVC_ADDI(t *testing.T) {
// ADDI where rd=rs1 and small imm → C.ADDI
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·caddi(SB), NOSPLIT, $0
ADDI X10, $5, X10
RET
`)
code := assembleRISCVHelper(t, fn)
// C.ADDI (2B) + C.JR (2B) = 4
if len(code) != 4 {
t.Errorf("expected 4 bytes, got %d", len(code))
}
}
func TestRISCV_RVC_LI(t *testing.T) {
// ADDI X0, $imm, rd → C.LI
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·cli(SB), NOSPLIT, $0
ADDI X0, $7, X10
RET
`)
code := assembleRISCVHelper(t, fn)
// C.LI (2B) + C.JR (2B) = 4
if len(code) != 4 {
t.Errorf("expected 4 bytes, got %d", len(code))
}
}
func TestRISCV_RVC_LUI(t *testing.T) {
// LUI rd, small nonzero imm → C.LUI
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·clui(SB), NOSPLIT, $0
LUI X10, $1
RET
`)
code := assembleRISCVHelper(t, fn)
// C.LUI (2B) + C.JR (2B) = 4
if len(code) != 4 {
t.Errorf("expected 4 bytes, got %d", len(code))
}
}
func TestRISCV_AssembleFile(t *testing.T) {
src := `#include "textflag.h"
TEXT ·add(SB), NOSPLIT, $0-24
MOV a+0(FP), X10
RET
TEXT ·sub(SB), NOSPLIT, $0
SUB X10, X11, X12
RET
`
f, errs := parser.Parse("t_riscv64.s", src)
if len(errs) > 0 {
t.Fatalf("parse: %v", errs)
}
img, err := AssembleFileRISCV(f)
if err != nil {
t.Fatalf("AssembleFileRISCV: %v", err)
}
if len(img.Funcs) != 2 {
t.Fatalf("expected 2 functions, got %d", len(img.Funcs))
}
// func add: C.LDSP(2) + C.JR(2) = 4
if img.Funcs[0].Size != 4 {
t.Errorf("add: expected 4 bytes, got %d", img.Funcs[0].Size)
}
// func sub: SUB(4) + C.JR(2) = 6
if img.Funcs[1].Size != 6 {
t.Errorf("sub: expected 6 bytes, got %d", img.Funcs[1].Size)
}
}
func TestRISCV_encodings(t *testing.T) {
// Smoke test that all known RISC-V mnemonics encode successfully.
tests := []struct {
name, src string
wantBytes int
}{
{"ADD", "ADD X10, X11, X12\nRET\n", 6},
{"SUBW", "SUBW X10, X11, X12\nRET\n", 6},
{"MUL", "MUL X10, X11, X12\nRET\n", 6},
{"DIVW", "DIVW X10, X11, X12\nRET\n", 6},
{"REMUW", "REMUW X10, X11, X12\nRET\n", 6},
{"ADDIW", "ADDIW X10, $5, X11\nRET\n", 6},
{"SLLI", "SLLI X10, $3, X11\nRET\n", 6}, // ADDI+SLLI? No, SLLI uses I-type
{"SRLI", "SRLI X10, $2, X11\nRET\n", 6},
{"SRAI", "SRAI X10, $1, X11\nRET\n", 6},
{"LB", "LB (X10), X11\nRET\n", 6},
{"LBU", "LBU (X10), X11\nRET\n", 6},
{"LH", "LH (X10), X11\nRET\n", 6},
{"LHU", "LHU (X10), X11\nRET\n", 6},
{"LWU", "LWU (X10), X11\nRET\n", 6},
{"SB", "SB X10, (X11)\nRET\n", 6},
{"SH", "SH X10, (X11)\nRET\n", 6},
{"SW", "SW X10, (X11)\nRET\n", 6},
{"LUI", "LUI X10, $0x12345\nRET\n", 6},
{"AUIPC", "AUIPC X10, $0\nRET\n", 6},
{"FLW", "FLW (X10), F10\nRET\n", 6},
{"FSW", "FSW F10, (X11)\nRET\n", 6},
{"FADDS", "FADDS F10, F11, F12\nRET\n", 6},
{"FMINS", "FMINS F10, F11, F12\nRET\n", 6},
{"FMAXD", "FMAXD F10, F11, F12\nRET\n", 6},
{"FCVTSD", "FCVTSD F10, F11\nRET\n", 6},
{"FCVTDS", "FCVTDS F10, F11\nRET\n", 6},
{"FMVXW", "FMVXW F10, X10\nRET\n", 6},
{"FMADD_S", "FMADDS F10, F11, F12, F13\nRET\n", 6},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·`+tt.name+`(SB), NOSPLIT, $0
`+tt.src)
code := assembleRISCVHelper(t, fn)
if len(code) != tt.wantBytes {
t.Errorf("expected %d bytes, got %d", tt.wantBytes, len(code))
}
})
}
}
func TestRISCV_RVC_branch(t *testing.T) {
// BEQ rs, X0, target → C.BEQZ when rs is in prime regs and offset fits.
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·cbeqz(SB), NOSPLIT, $0
ADDI X10, $1, X10
BEQ X10, X0, done
ADDI X10, $1, X10
done:
RET
`)
code := assembleRISCVHelper(t, fn)
// C.ADDI(2) + C.BEQZ(2) + C.ADDI(2) + C.JR(2) = 8 (all compress)
if len(code) != 8 {
t.Errorf("expected 8 bytes with C.BEQZ, got %d", len(code))
}
}
func TestRISCV_RVC_CJ(t *testing.T) {
// JMP target → C.J when offset fits.
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·cj(SB), NOSPLIT, $0
JMP done
done:
RET
`)
code := assembleRISCVHelper(t, fn)
// C.J(2) + C.JR(2) = 4
if len(code) != 4 {
t.Errorf("expected 4 bytes with C.J, got %d", len(code))
}
}
func TestRISCV_RVC_CADD(t *testing.T) {
// ADD where rd==rs1 and both in prime regs → C.ADD.
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·cadd(SB), NOSPLIT, $0
ADD X10, X11, X10
RET
`)
code := assembleRISCVHelper(t, fn)
// C.ADD(2) + C.JR(2) = 4
if len(code) != 4 {
t.Errorf("expected 4 bytes with C.ADD, got %d", len(code))
}
}
func TestRISCV_RVC_CADD_commute(t *testing.T) {
// ADD where rd==rs2 (commutative swap) → C.ADD.
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·cadd2(SB), NOSPLIT, $0
ADD X11, X10, X10
RET
`)
code := assembleRISCVHelper(t, fn)
// C.ADD(2) + C.JR(2) = 4
if len(code) != 4 {
t.Errorf("expected 4 bytes with C.ADD (commuted), got %d", len(code))
}
}
func TestRISCV_RVC_CSUB(t *testing.T) {
// SUB where rd==rs1 and both in prime regs → C.SUB.
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·csub(SB), NOSPLIT, $0
SUB X11, X10, X10
RET
`)
code := assembleRISCVHelper(t, fn)
// SUB X11,X10,X10 → rd=X10, rs1=X11 ≠ rd → no C.SUB.
// Plan9: INSTR src1, src2, dst. For C.SUB: rd must equal rs1.
// So: SUB X10, X11, X10 → rd=10, rs1=10, rs2=11 ✓
if len(code) == 4 {
return // compressed
}
// Try with correct operand order.
fn2 := firstTextRISCV(t, `#include "textflag.h"
TEXT ·csub2(SB), NOSPLIT, $0
SUB X10, X11, X10
RET
`)
code2 := assembleRISCVHelper(t, fn2)
if len(code2) != 4 {
t.Errorf("expected 4 bytes with C.SUB, got %d (% x)", len(code2), code2)
}
}
func TestRISCV_RVC_CXOR(t *testing.T) {
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·cxor(SB), NOSPLIT, $0
XOR X10, X11, X10
RET
`)
code := assembleRISCVHelper(t, fn)
if len(code) != 4 {
t.Errorf("expected 4 bytes with C.XOR, got %d", len(code))
}
}
func TestRISCV_RVC_COR(t *testing.T) {
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·cor(SB), NOSPLIT, $0
OR X10, X11, X10
RET
`)
code := assembleRISCVHelper(t, fn)
if len(code) != 4 {
t.Errorf("expected 4 bytes with C.OR, got %d", len(code))
}
}
func TestRISCV_RVC_CAND(t *testing.T) {
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·cand(SB), NOSPLIT, $0
AND X10, X11, X10
RET
`)
code := assembleRISCVHelper(t, fn)
if len(code) != 4 {
t.Errorf("expected 4 bytes with C.AND, got %d", len(code))
}
}
func TestRISCV_RVC_CFLDSP(t *testing.T) {
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·cfldsp(SB), NOSPLIT, $0-8
FLD a+0(FP), F10
RET
`)
code := assembleRISCVHelper(t, fn)
// C.FLDSP(2) + C.JR(2) = 4
if len(code) != 4 {
t.Errorf("expected 4 bytes with C.FLDSP, got %d", len(code))
}
}
func TestRISCV_RVC_CFSDSP(t *testing.T) {
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·cfsdsp(SB), NOSPLIT, $0-8
FSD F10, ret+0(FP)
RET
`)
code := assembleRISCVHelper(t, fn)
// C.FSDSP(2) + C.JR(2) = 4
if len(code) != 4 {
t.Errorf("expected 4 bytes with C.FSDSP, got %d", len(code))
}
}
func TestRISCV_SB_addr(t *testing.T) {
// MOV $sym<>(SB), rd → AUIPC + ADDI (8 bytes for SB).
src := `#include "textflag.h"
TEXT ·sbaddr(SB), NOSPLIT, $0
MOV $answer<>(SB), X10
RET
GLOBL answer<>(SB), RODATA, $8
DATA answer<>+0(SB)/8, $42
`
f, errs := parser.Parse("t_riscv64.s", src)
if len(errs) > 0 {
t.Fatalf("parse: %v", errs)
}
img, err := AssembleFileRISCV(f)
if err != nil {
t.Fatalf("AssembleFileRISCV: %v", err)
}
// AUIPC(4) + ADDI(4) + C.JR(2) = 10
if img.Funcs[0].Size != 10 {
t.Errorf("expected 10 bytes, got %d", img.Funcs[0].Size)
}
}
func TestRISCV_SB_store(t *testing.T) {
// MOV rd, sym<>(SB) → AUIPC + SD (8 bytes for SB).
src := `#include "textflag.h"
TEXT ·sbstore(SB), NOSPLIT, $0
MOV X10, result<>(SB)
RET
GLOBL result<>(SB), NOPTR, $8
`
f, errs := parser.Parse("t_riscv64.s", src)
if len(errs) > 0 {
t.Fatalf("parse: %v", errs)
}
img, err := AssembleFileRISCV(f)
if err != nil {
t.Fatalf("AssembleFileRISCV: %v", err)
}
// AUIPC X31(4) + SD X10,0(X31)(4) + C.JR(2) = 10
if img.Funcs[0].Size != 10 {
t.Errorf("expected 10 bytes, got %d", img.Funcs[0].Size)
}
}
func TestRISCV_ELF(t *testing.T) {
src := `#include "textflag.h"
TEXT ·simple(SB), NOSPLIT, $0
RET
`
f, errs := parser.Parse("t_riscv64.s", src)
if len(errs) > 0 {
t.Fatalf("parse: %v", errs)
}
img, err := AssembleFileRISCV(f)
if err != nil {
t.Fatalf("AssembleFileRISCV: %v", err)
}
obj, err := img.ELFRISCVObject()
if err != nil {
t.Fatalf("ELFRISCVObject: %v", err)
}
if len(obj) < 4 || obj[0] != 0x7f || obj[1] != 'E' || obj[2] != 'L' || obj[3] != 'F' {
t.Fatal("not a valid ELF file")
}
if len(obj) >= 20 {
machine := uint16(obj[18]) | uint16(obj[19])<<8
if machine != 243 {
t.Errorf("e_machine = %d, want 243 (EM_RISCV)", machine)
}
}
}
func TestRISCV_ELF_withData(t *testing.T) {
src := `#include "textflag.h"
TEXT ·get(SB), NOSPLIT, $0
RET
GLOBL val<>(SB), RODATA, $4
DATA val<>+0(SB)/4, $7
`
f, errs := parser.Parse("t_riscv64.s", src)
if len(errs) > 0 {
t.Fatalf("parse: %v", errs)
}
img, err := AssembleFileRISCV(f)
if err != nil {
t.Fatalf("AssembleFileRISCV: %v", err)
}
if len(img.DataSyms) != 1 {
t.Fatalf("expected 1 data symbol, got %d", len(img.DataSyms))
}
if img.DataSyms[0].Name != "val" {
t.Errorf("data symbol name = %q, want val", img.DataSyms[0].Name)
}
if img.DataSyms[0].Size != 4 {
t.Errorf("data symbol size = %d, want 4", img.DataSyms[0].Size)
}
obj, err := img.ELFRISCVObject()
if err != nil {
t.Fatalf("ELFRISCVObject: %v", err)
}
_ = obj
}
func TestRISCV_SB_load(t *testing.T) {
// MOV sym<>(SB), rd → AUIPC + LD (8 bytes for SB).
src := `#include "textflag.h"
TEXT ·sbload(SB), NOSPLIT, $0
MOV answer<>(SB), X10
RET
GLOBL answer<>(SB), RODATA, $8
DATA answer<>+0(SB)/8, $42
`
f, errs := parser.Parse("t_riscv64.s", src)
if len(errs) > 0 {
t.Fatalf("parse: %v", errs)
}
img, err := AssembleFileRISCV(f)
if err != nil {
t.Fatalf("AssembleFileRISCV: %v", err)
}
// AUIPC(4) + LD(4) + C.JR(2) = 10
if img.Funcs[0].Size != 10 {
t.Errorf("expected 10 bytes, got %d", img.Funcs[0].Size)
}
}
func TestRISCV_system_instrs(t *testing.T) {
// Test FENCE, ECALL, EBREAK encoding.
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·sys(SB), NOSPLIT, $0
FENCE
ECALL
EBREAK
RET
`)
code := assembleRISCVHelper(t, fn)
// 3 system instructions × 4 bytes + C.JR(2) = 14
if len(code) != 14 {
t.Errorf("expected 14 bytes, got %d (% x)", len(code), code)
}
}
func TestRISCV_MOV_sym_FP_error(t *testing.T) {
// MOV $sym(FP), rd should return an error (unsupported).
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·badfp(SB), NOSPLIT, $0
MOV $arg(FP), X10
RET
`)
_, _, _, err := assembleRISCV(fn)
if err == nil {
t.Error("expected error for MOV $arg(FP), got nil")
}
}
func TestRISCV_CALL(t *testing.T) {
// CALL target → AUIPC + JALR (8 bytes).
fn := firstTextRISCV(t, `#include "textflag.h"
TEXT ·calltest(SB), NOSPLIT, $0
CALL sub
done:
RET
sub:
RET
`)
code := assembleRISCVHelper(t, fn)
// CALL(8) + C.JR(2) + C.JR(2) = 12
if len(code) != 12 {
t.Errorf("expected 12 bytes with CALL, got %d", len(code))
}
}