[PULL 42/66] target/mips: Alias MSA vector registers on FPU scalar registers

[Philippe Mathieu-Daudé]

Commits 863f264d10f ("add msa_reset(), global msa register") and
cb269f273fd ("fix multiple TCG registers covering same data")
removed the FPU scalar registers and replaced them by aliases to
the MSA vector registers.

It is not very clear to have FPU registers displayed with MSA
register names, even if MSA ASE is not present.

Instead of aliasing FPU registers to the MSA ones (even when MSA
is absent), we now alias the MSA ones to the FPU ones (only when
MSA is present).

Reviewed-by: Jiaxun Yang <jiaxun.yang at flygoat.com>
Reviewed-by: Richard Henderson <richard.henderson at linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug at amsat.org>
Tested-by: Jiaxun Yang <jiaxun.yang at flygoat.com>
Message-Id: <20201208003702.4088927-7-f4bug at amsat.org>
---
 target/mips/translate.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/target/mips/translate.c b/target/mips/translate.c
index e3cea5899f3..30354fee828 100644
--- a/target/mips/translate.c
+++ b/target/mips/translate.c
@@ -31561,16 +31561,20 @@ void mips_tcg_init(void)
                                         offsetof(CPUMIPSState,
                                                  active_tc.gpr[i]),
                                         regnames[i]);
-
     for (i = 0; i < 32; i++) {
         int off = offsetof(CPUMIPSState, active_fpu.fpr[i].wr.d[0]);
-        msa_wr_d[i * 2] =
-                tcg_global_mem_new_i64(cpu_env, off, msaregnames[i * 2]);
+
+        fpu_f64[i] = tcg_global_mem_new_i64(cpu_env, off, fregnames[i]);
+    }
+    /* MSA */
+    for (i = 0; i < 32; i++) {
+        int off = offsetof(CPUMIPSState, active_fpu.fpr[i].wr.d[0]);
+
         /*
-         * The scalar floating-point unit (FPU) registers are mapped on
-         * the MSA vector registers.
+         * The MSA vector registers are mapped on the
+         * scalar floating-point unit (FPU) registers.
          */
-        fpu_f64[i] = msa_wr_d[i * 2];
+        msa_wr_d[i * 2] = fpu_f64[i];
         off = offsetof(CPUMIPSState, active_fpu.fpr[i].wr.d[1]);
         msa_wr_d[i * 2 + 1] =
                 tcg_global_mem_new_i64(cpu_env, off, msaregnames[i * 2 + 1]);
-- 
2.26.2