[PATCH v3 2/6] tcg/riscv64: Use a uimm5 encoder for vector shift immediates

["Philippe Mathieu-Daudé" <philmd@oss.qualcomm.com>]

RVV shift .vi forms take an unsigned 5-bit immediate, but
encode_vi() checks for simm5, so shift counts 16..31 trip
the debug assertion (and are undefined behaviour in release
builds).

Add encode_vi_u() and use it in tcg_out_vshifti().

Fixes: 006352d69f14 ("tcg/riscv64: Assert immediate in range ...")
Signed-off-by: Philippe Mathieu-Daudé <philmd@oss.qualcomm.com>
---
 tcg/riscv64/tcg-target.c.inc | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/tcg/riscv64/tcg-target.c.inc b/tcg/riscv64/tcg-target.c.inc
index 712170c1203e..0e749ae296b8 100644
--- a/tcg/riscv64/tcg-target.c.inc
+++ b/tcg/riscv64/tcg-target.c.inc
@@ -541,6 +541,7 @@ static tcg_insn_unit encode_vi_raw(RISCVInsn opc, TCGReg rd, unsigned imm5,
            (vs2 & 0x1f) << 20 | (vm << 25);
 }
 
+/* OPIVI with a signed immediate (simm5). */
 static tcg_insn_unit encode_vi(RISCVInsn opc, TCGReg rd, tcg_target_long imm,
                                TCGReg vs2, bool vm)
 {
@@ -548,6 +549,14 @@ static tcg_insn_unit encode_vi(RISCVInsn opc, TCGReg rd, tcg_target_long imm,
     return encode_vi_raw(opc, rd, imm, vs2, vm);
 }
 
+/* OPIVI with an unsigned immediate (uimm5) */
+static tcg_insn_unit encode_vi_u(RISCVInsn opc, TCGReg rd, unsigned imm,
+                                 TCGReg vs2, bool vm)
+{
+    tcg_debug_assert(imm == extract32(imm, 0, 5));
+    return encode_vi_raw(opc, rd, imm, vs2, vm);
+}
+
 /* Type-OPIVV/OPMVV/OPIVX/OPMVX, Vector load and store */
 
 static tcg_insn_unit encode_v(RISCVInsn opc, TCGReg d, TCGReg s1,
@@ -720,6 +729,12 @@ static void tcg_out_opc_vi(TCGContext *s, RISCVInsn opc,
     tcg_out32(s, encode_vi(opc, vd, imm, vs2, true));
 }
 
+static void tcg_out_opc_vi_u(TCGContext *s, RISCVInsn opc,
+                             TCGReg vd, TCGReg vs2, unsigned imm)
+{
+    tcg_out32(s, encode_vi_u(opc, vd, imm, vs2, true));
+}
+
 static void tcg_out_opc_vv_vi(TCGContext *s, RISCVInsn o_vv, RISCVInsn o_vi,
                               TCGReg vd, TCGReg vs2, TCGArg vi1, int c_vi1)
 {
@@ -1578,7 +1593,7 @@ static void tcg_out_vshifti(TCGContext *s, RISCVInsn opc_vi, RISCVInsn opc_vx,
                              TCGReg dst, TCGReg src, unsigned imm)
 {
     if (imm < 32) {
-        tcg_out_opc_vi(s, opc_vi, dst, src, imm);
+        tcg_out_opc_vi_u(s, opc_vi, dst, src, imm);
     } else {
         tcg_out_movi(s, TCG_TYPE_I32, TCG_REG_TMP0, imm);
         tcg_out_opc_vx(s, opc_vx, dst, src, TCG_REG_TMP0);
-- 
2.55.0