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[PATCH 08/17] target/riscv: Use gpr_{src, dst} for word shift operations


From: Richard Henderson
Subject: [PATCH 08/17] target/riscv: Use gpr_{src, dst} for word shift operations
Date: Thu, 8 Jul 2021 21:25:59 -0700

For trans_sllw, we can just use gen_shiftw.  The others use
various tricks to reduce the tcg operation count.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/riscv/insn_trans/trans_rvi.c.inc | 82 ++++++++++---------------
 1 file changed, 31 insertions(+), 51 deletions(-)

diff --git a/target/riscv/insn_trans/trans_rvi.c.inc 
b/target/riscv/insn_trans/trans_rvi.c.inc
index a422dc9ef4..840187a4d6 100644
--- a/target/riscv/insn_trans/trans_rvi.c.inc
+++ b/target/riscv/insn_trans/trans_rvi.c.inc
@@ -352,24 +352,23 @@ static bool trans_slliw(DisasContext *ctx, arg_slliw *a)
 static bool trans_srliw(DisasContext *ctx, arg_srliw *a)
 {
     REQUIRE_64BIT(ctx);
-    TCGv t = tcg_temp_new();
-    gen_get_gpr(t, a->rs1);
-    tcg_gen_extract_tl(t, t, a->shamt, 32 - a->shamt);
-    /* sign-extend for W instructions */
-    tcg_gen_ext32s_tl(t, t);
-    gen_set_gpr(a->rd, t);
-    tcg_temp_free(t);
+
+    TCGv dest = gpr_dst(ctx, a->rd);
+    TCGv src1 = gpr_src(ctx, a->rs1);
+
+    tcg_gen_extract_tl(dest, src1, a->shamt, 32 - a->shamt);
+    tcg_gen_ext32s_tl(dest, dest);
     return true;
 }
 
 static bool trans_sraiw(DisasContext *ctx, arg_sraiw *a)
 {
     REQUIRE_64BIT(ctx);
-    TCGv t = tcg_temp_new();
-    gen_get_gpr(t, a->rs1);
-    tcg_gen_sextract_tl(t, t, a->shamt, 32 - a->shamt);
-    gen_set_gpr(a->rd, t);
-    tcg_temp_free(t);
+
+    TCGv dest = gpr_dst(ctx, a->rd);
+    TCGv src1 = gpr_src(ctx, a->rs1);
+
+    tcg_gen_sextract_tl(dest, src1, a->shamt, 32 - a->shamt);
     return true;
 }
 
@@ -388,64 +387,45 @@ static bool trans_subw(DisasContext *ctx, arg_subw *a)
 static bool trans_sllw(DisasContext *ctx, arg_sllw *a)
 {
     REQUIRE_64BIT(ctx);
-    TCGv source1 = tcg_temp_new();
-    TCGv source2 = tcg_temp_new();
-
-    gen_get_gpr(source1, a->rs1);
-    gen_get_gpr(source2, a->rs2);
-
-    tcg_gen_andi_tl(source2, source2, 0x1F);
-    tcg_gen_shl_tl(source1, source1, source2);
-
-    tcg_gen_ext32s_tl(source1, source1);
-    gen_set_gpr(a->rd, source1);
-    tcg_temp_free(source1);
-    tcg_temp_free(source2);
-    return true;
+    return gen_shiftw(ctx, a, tcg_gen_shl_tl);
 }
 
 static bool trans_srlw(DisasContext *ctx, arg_srlw *a)
 {
     REQUIRE_64BIT(ctx);
-    TCGv source1 = tcg_temp_new();
-    TCGv source2 = tcg_temp_new();
 
-    gen_get_gpr(source1, a->rs1);
-    gen_get_gpr(source2, a->rs2);
+    TCGv dest = gpr_dst(ctx, a->rd);
+    TCGv src1 = gpr_src(ctx, a->rs1);
+    TCGv src2 = gpr_src(ctx, a->rs2);
+    TCGv ext2 = tcg_temp_new();
 
-    /* clear upper 32 */
-    tcg_gen_ext32u_tl(source1, source1);
-    tcg_gen_andi_tl(source2, source2, 0x1F);
-    tcg_gen_shr_tl(source1, source1, source2);
+    tcg_gen_andi_tl(ext2, src2, 31);
+    tcg_gen_ext32u_tl(dest, src1);
+    tcg_gen_shr_tl(dest, dest, ext2);
+    tcg_gen_ext32s_tl(dest, dest);
 
-    tcg_gen_ext32s_tl(source1, source1);
-    gen_set_gpr(a->rd, source1);
-    tcg_temp_free(source1);
-    tcg_temp_free(source2);
+    tcg_temp_free(ext2);
     return true;
 }
 
 static bool trans_sraw(DisasContext *ctx, arg_sraw *a)
 {
     REQUIRE_64BIT(ctx);
-    TCGv source1 = tcg_temp_new();
-    TCGv source2 = tcg_temp_new();
 
-    gen_get_gpr(source1, a->rs1);
-    gen_get_gpr(source2, a->rs2);
+    TCGv dest = gpr_dst(ctx, a->rd);
+    TCGv src1 = gpr_src(ctx, a->rs1);
+    TCGv src2 = gpr_src(ctx, a->rs2);
+    TCGv ext2 = tcg_temp_new();
 
+    tcg_gen_andi_tl(ext2, src2, 31);
     /*
-     * first, trick to get it to act like working on 32 bits (get rid of
-     * upper 32, sign extend to fill space)
+     * First, trick to get it to act like working on 32 bits
+     * (get rid of upper 32, sign extend to fill space)
      */
-    tcg_gen_ext32s_tl(source1, source1);
-    tcg_gen_andi_tl(source2, source2, 0x1F);
-    tcg_gen_sar_tl(source1, source1, source2);
-
-    gen_set_gpr(a->rd, source1);
-    tcg_temp_free(source1);
-    tcg_temp_free(source2);
+    tcg_gen_ext32s_tl(dest, src1);
+    tcg_gen_sar_tl(dest, dest, ext2);
 
+    tcg_temp_free(ext2);
     return true;
 }
 
-- 
2.25.1




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