[PATCH 0/4] target/alpha: Use tcg_constant_*

[PATCH 0/4] target/alpha: Use tcg_constant_*

[Richard Henderson]

Replace use of tcg_const_*, which makes a copy into a temp
which must be freed, with direct use of the constant.


r~


Richard Henderson (4):
  target/alpha: Store set into rx flag
  target/alpha: Use dest_sink for HW_RET temporary
  target/alpha: Use tcg_constant_i64 for zero and lit
  target/alpha: Use tcg_constant_* elsewhere

 target/alpha/translate.c | 70 +++++++++++-----------------------------
 1 file changed, 18 insertions(+), 52 deletions(-)

-- 
2.25.1

[PATCH 1/4] target/alpha: Store set into rx flag

[Richard Henderson]

A paste-o meant that we wrote back the existing value
of the RX flag rather than changing it to TMP.

Use tcg_constant_i64 while we're at it.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/alpha/translate.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/target/alpha/translate.c b/target/alpha/translate.c
index f2922f5f8c..d8bd47de75 100644
--- a/target/alpha/translate.c
+++ b/target/alpha/translate.c
@@ -1116,15 +1116,11 @@ static void gen_msk_l(DisasContext *ctx, TCGv vc, TCGv va, int rb, bool islit,
 
 static void gen_rx(DisasContext *ctx, int ra, int set)
 {
-    TCGv tmp;
-
     if (ra != 31) {
         ld_flag_byte(ctx->ir[ra], ENV_FLAG_RX_SHIFT);
     }
 
-    tmp = tcg_const_i64(set);
-    st_flag_byte(ctx->ir[ra], ENV_FLAG_RX_SHIFT);
-    tcg_temp_free(tmp);
+    st_flag_byte(tcg_constant_i64(set), ENV_FLAG_RX_SHIFT);
 }
 
 static DisasJumpType gen_call_pal(DisasContext *ctx, int palcode)
-- 
2.25.1

[PATCH 2/4] target/alpha: Use dest_sink for HW_RET temporary

[Richard Henderson]

This temp is automatically freed, just like ctx->lit.
But we're about to remove ctx->lit, so use sink instead.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/alpha/translate.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/target/alpha/translate.c b/target/alpha/translate.c
index d8bd47de75..5ea091eef5 100644
--- a/target/alpha/translate.c
+++ b/target/alpha/translate.c
@@ -2749,7 +2749,7 @@ static DisasJumpType translate_one(DisasContext *ctx, uint32_t insn)
             /* Pre-EV6 CPUs interpreted this as HW_REI, loading the return
                address from EXC_ADDR.  This turns out to be useful for our
                emulation PALcode, so continue to accept it.  */
-            ctx->lit = vb = tcg_temp_new();
+            vb = dest_sink(ctx);
             tcg_gen_ld_i64(vb, cpu_env, offsetof(CPUAlphaState, exc_addr));
         } else {
             vb = load_gpr(ctx, rb);
-- 
2.25.1

Re: [PATCH 2/4] target/alpha: Use dest_sink for HW_RET temporary

[Philippe Mathieu-Daudé]

On 7/8/21 8:25 PM, Richard Henderson wrote:
> This temp is automatically freed, just like ctx->lit.
> But we're about to remove ctx->lit, so use sink instead.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  target/alpha/translate.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

[PATCH 3/4] target/alpha: Use tcg_constant_i64 for zero and lit

[Richard Henderson]

These constant temps do not need to be freed, and
therefore need less bookkeeping from tcg producers.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/alpha/translate.c | 16 ++--------------
 1 file changed, 2 insertions(+), 14 deletions(-)

diff --git a/target/alpha/translate.c b/target/alpha/translate.c
index 5ea091eef5..3fd66fb78d 100644
--- a/target/alpha/translate.c
+++ b/target/alpha/translate.c
@@ -67,8 +67,6 @@ struct DisasContext {
     /* Temporaries for $31 and $f31 as source and destination.  */
     TCGv zero;
     TCGv sink;
-    /* Temporary for immediate constants.  */
-    TCGv lit;
 };
 
 /* Target-specific return values from translate_one, indicating the
@@ -158,7 +156,7 @@ void alpha_translate_init(void)
 static TCGv load_zero(DisasContext *ctx)
 {
     if (!ctx->zero) {
-        ctx->zero = tcg_const_i64(0);
+        ctx->zero = tcg_constant_i64(0);
     }
     return ctx->zero;
 }
@@ -178,14 +176,6 @@ static void free_context_temps(DisasContext *ctx)
         tcg_temp_free(ctx->sink);
         ctx->sink = NULL;
     }
-    if (ctx->zero) {
-        tcg_temp_free(ctx->zero);
-        ctx->zero = NULL;
-    }
-    if (ctx->lit) {
-        tcg_temp_free(ctx->lit);
-        ctx->lit = NULL;
-    }
 }
 
 static TCGv load_gpr(DisasContext *ctx, unsigned reg)
@@ -201,8 +191,7 @@ static TCGv load_gpr_lit(DisasContext *ctx, unsigned reg,
                          uint8_t lit, bool islit)
 {
     if (islit) {
-        ctx->lit = tcg_const_i64(lit);
-        return ctx->lit;
+        return tcg_constant_i64(lit);
     } else if (likely(reg < 31)) {
         return ctx->ir[reg];
     } else {
@@ -3024,7 +3013,6 @@ static void alpha_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cpu)
 
     ctx->zero = NULL;
     ctx->sink = NULL;
-    ctx->lit = NULL;
 
     /* Bound the number of insns to execute to those left on the page.  */
     if (in_superpage(ctx, ctx->base.pc_first)) {
-- 
2.25.1

Re: [PATCH 3/4] target/alpha: Use tcg_constant_i64 for zero and lit

[Philippe Mathieu-Daudé]

On 7/8/21 8:25 PM, Richard Henderson wrote:
> These constant temps do not need to be freed, and
> therefore need less bookkeeping from tcg producers.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  target/alpha/translate.c | 16 ++--------------
>  1 file changed, 2 insertions(+), 14 deletions(-)

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

[PATCH 4/4] target/alpha: Use tcg_constant_* elsewhere

[Richard Henderson]

Replace the remaining uses of tcg_const_*.  These uses are
all local, with the allocate and free close together.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/alpha/translate.c | 46 ++++++++++++----------------------------
 1 file changed, 14 insertions(+), 32 deletions(-)

diff --git a/target/alpha/translate.c b/target/alpha/translate.c
index 3fd66fb78d..cf5ad46853 100644
--- a/target/alpha/translate.c
+++ b/target/alpha/translate.c
@@ -251,11 +251,9 @@ static void gen_excp_1(int exception, int error_code)
 {
     TCGv_i32 tmp1, tmp2;
 
-    tmp1 = tcg_const_i32(exception);
-    tmp2 = tcg_const_i32(error_code);
+    tmp1 = tcg_constant_i32(exception);
+    tmp2 = tcg_constant_i32(error_code);
     gen_helper_excp(cpu_env, tmp1, tmp2);
-    tcg_temp_free_i32(tmp2);
-    tcg_temp_free_i32(tmp1);
 }
 
 static DisasJumpType gen_excp(DisasContext *ctx, int exception, int error_code)
@@ -506,15 +504,11 @@ static DisasJumpType gen_bcond_internal(DisasContext *ctx, TCGCond cond,
 
         return DISAS_NORETURN;
     } else {
-        TCGv_i64 z = tcg_const_i64(0);
-        TCGv_i64 d = tcg_const_i64(dest);
-        TCGv_i64 p = tcg_const_i64(ctx->base.pc_next);
+        TCGv_i64 z = load_zero(ctx);
+        TCGv_i64 d = tcg_constant_i64(dest);
+        TCGv_i64 p = tcg_constant_i64(ctx->base.pc_next);
 
         tcg_gen_movcond_i64(cond, cpu_pc, cmp, z, d, p);
-
-        tcg_temp_free_i64(z);
-        tcg_temp_free_i64(d);
-        tcg_temp_free_i64(p);
         return DISAS_PC_UPDATED;
     }
 }
@@ -716,22 +710,19 @@ static void gen_fp_exc_raise(int rc, int fn11)
     if (!(fn11 & QUAL_I)) {
         ignore |= FPCR_INE;
     }
-    ign = tcg_const_i32(ignore);
+    ign = tcg_constant_i32(ignore);
 
     /* ??? Pass in the regno of the destination so that the helper can
        set EXC_MASK, which contains a bitmask of destination registers
        that have caused arithmetic traps.  A simple userspace emulation
        does not require this.  We do need it for a guest kernel's entArith,
        or if we were to do something clever with imprecise exceptions.  */
-    reg = tcg_const_i32(rc + 32);
+    reg = tcg_constant_i32(rc + 32);
     if (fn11 & QUAL_S) {
         gen_helper_fp_exc_raise_s(cpu_env, ign, reg);
     } else {
         gen_helper_fp_exc_raise(cpu_env, ign, reg);
     }
-
-    tcg_temp_free_i32(reg);
-    tcg_temp_free_i32(ign);
 }
 
 static void gen_cvtlq(TCGv vc, TCGv vb)
@@ -824,7 +815,7 @@ IEEE_INTCVT(cvtqt)
 
 static void gen_cpy_mask(TCGv vc, TCGv va, TCGv vb, bool inv_a, uint64_t mask)
 {
-    TCGv vmask = tcg_const_i64(mask);
+    TCGv vmask = tcg_constant_i64(mask);
     TCGv tmp = tcg_temp_new_i64();
 
     if (inv_a) {
@@ -836,7 +827,6 @@ static void gen_cpy_mask(TCGv vc, TCGv va, TCGv vb, bool inv_a, uint64_t mask)
     tcg_gen_andc_i64(vc, vb, vmask);
     tcg_gen_or_i64(vc, vc, tmp);
 
-    tcg_temp_free(vmask);
     tcg_temp_free(tmp);
 }
 
@@ -1210,12 +1200,9 @@ static DisasJumpType gen_call_pal(DisasContext *ctx, int palcode)
 
         case 0x3E:
             /* WTINT */
-            {
-                TCGv_i32 tmp = tcg_const_i32(1);
-                tcg_gen_st_i32(tmp, cpu_env, -offsetof(AlphaCPU, env) +
-                                             offsetof(CPUState, halted));
-                tcg_temp_free_i32(tmp);
-            }
+            tcg_gen_st_i32(tcg_constant_i32(1), cpu_env,
+                           -offsetof(AlphaCPU, env) +
+                           offsetof(CPUState, halted));
             tcg_gen_movi_i64(ctx->ir[IR_V0], 0);
             return gen_excp(ctx, EXCP_HALTED, 0);
 
@@ -1366,12 +1353,8 @@ static DisasJumpType gen_mtpr(DisasContext *ctx, TCGv vb, int regno)
 
     case 253:
         /* WAIT */
-        {
-            TCGv_i32 tmp = tcg_const_i32(1);
-            tcg_gen_st_i32(tmp, cpu_env, -offsetof(AlphaCPU, env) +
-                                         offsetof(CPUState, halted));
-            tcg_temp_free_i32(tmp);
-        }
+        tcg_gen_st_i32(tcg_constant_i32(1), cpu_env,
+                       -offsetof(AlphaCPU, env) + offsetof(CPUState, halted));
         return gen_excp(ctx, EXCP_HALTED, 0);
 
     case 252:
@@ -2744,9 +2727,8 @@ static DisasJumpType translate_one(DisasContext *ctx, uint32_t insn)
             vb = load_gpr(ctx, rb);
         }
         tcg_gen_movi_i64(cpu_lock_addr, -1);
+        st_flag_byte(load_zero(ctx), ENV_FLAG_RX_SHIFT);
         tmp = tcg_temp_new();
-        tcg_gen_movi_i64(tmp, 0);
-        st_flag_byte(tmp, ENV_FLAG_RX_SHIFT);
         tcg_gen_andi_i64(tmp, vb, 1);
         st_flag_byte(tmp, ENV_FLAG_PAL_SHIFT);
         tcg_temp_free(tmp);
-- 
2.25.1

Re: [PATCH 4/4] target/alpha: Use tcg_constant_* elsewhere

[Philippe Mathieu-Daudé]

On 7/8/21 8:25 PM, Richard Henderson wrote:
> Replace the remaining uses of tcg_const_*.  These uses are
> all local, with the allocate and free close together.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  target/alpha/translate.c | 46 ++++++++++++----------------------------
>  1 file changed, 14 insertions(+), 32 deletions(-)

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>