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From: Peter Maydell <peter.maydell@linaro.org>
To: qemu-devel@nongnu.org
Subject: [Qemu-devel] [PULL 25/29] target/arm: Remove redundant shift tests
Date: Fri, 16 Aug 2019 14:17:15 +0100
Message-ID: <20190816131719.28244-26-peter.maydell@linaro.org> (raw)
In-Reply-To: <20190816131719.28244-1-peter.maydell@linaro.org>

From: Richard Henderson <richard.henderson@linaro.org>

The immediate shift generator functions already test for,
and eliminate, the case of a shift by zero.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190808202616.13782-4-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/translate.c | 19 +++++++------------
 1 file changed, 7 insertions(+), 12 deletions(-)

diff --git a/target/arm/translate.c b/target/arm/translate.c
index 9c3323509e1..ebc7c67f025 100644
--- a/target/arm/translate.c
+++ b/target/arm/translate.c
@@ -8811,8 +8811,7 @@ static void disas_arm_insn(DisasContext *s, unsigned int insn)
                         shift = (insn >> 10) & 3;
                         /* ??? In many cases it's not necessary to do a
                            rotate, a shift is sufficient.  */
-                        if (shift != 0)
-                            tcg_gen_rotri_i32(tmp, tmp, shift * 8);
+                        tcg_gen_rotri_i32(tmp, tmp, shift * 8);
                         op1 = (insn >> 20) & 7;
                         switch (op1) {
                         case 0: gen_sxtb16(tmp);  break;
@@ -9889,8 +9888,7 @@ static void disas_thumb2_insn(DisasContext *s, uint32_t insn)
             shift = (insn >> 4) & 3;
             /* ??? In many cases it's not necessary to do a
                rotate, a shift is sufficient.  */
-            if (shift != 0)
-                tcg_gen_rotri_i32(tmp, tmp, shift * 8);
+            tcg_gen_rotri_i32(tmp, tmp, shift * 8);
             op = (insn >> 20) & 7;
             switch (op) {
             case 0: gen_sxth(tmp);   break;
@@ -10617,11 +10615,10 @@ static void disas_thumb2_insn(DisasContext *s, uint32_t insn)
                     case 7:
                         goto illegal_op;
                     default: /* Saturate.  */
-                        if (shift) {
-                            if (op & 1)
-                                tcg_gen_sari_i32(tmp, tmp, shift);
-                            else
-                                tcg_gen_shli_i32(tmp, tmp, shift);
+                        if (op & 1) {
+                            tcg_gen_sari_i32(tmp, tmp, shift);
+                        } else {
+                            tcg_gen_shli_i32(tmp, tmp, shift);
                         }
                         tmp2 = tcg_const_i32(imm);
                         if (op & 4) {
@@ -10812,9 +10809,7 @@ static void disas_thumb2_insn(DisasContext *s, uint32_t insn)
                     goto illegal_op;
                 }
                 tmp = load_reg(s, rm);
-                if (shift) {
-                    tcg_gen_shli_i32(tmp, tmp, shift);
-                }
+                tcg_gen_shli_i32(tmp, tmp, shift);
                 tcg_gen_add_i32(addr, addr, tmp);
                 tcg_temp_free_i32(tmp);
                 break;
-- 
2.20.1



  parent reply index

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-16 13:16 [Qemu-devel] [PULL 00/29] target-arm queue Peter Maydell
2019-08-16 13:16 ` [Qemu-devel] [PULL 01/29] target/arm: generate a custom MIDR for -cpu max Peter Maydell
2019-08-16 13:16 ` [Qemu-devel] [PULL 02/29] hw/misc/zynq_slcr: use standard register definition Peter Maydell
2019-08-16 13:16 ` [Qemu-devel] [PULL 03/29] Set ENET_BD_BDU in I.MX FEC controller Peter Maydell
2019-08-16 13:16 ` [Qemu-devel] [PULL 04/29] target/arm: Factor out 'generate singlestep exception' function Peter Maydell
2019-08-16 13:16 ` [Qemu-devel] [PULL 05/29] target/arm: Fix routing of singlestep exceptions Peter Maydell
2019-08-16 13:16 ` [Qemu-devel] [PULL 06/29] target/arm: Pass in pc to thumb_insn_is_16bit Peter Maydell
2019-08-16 13:16 ` [Qemu-devel] [PULL 07/29] target/arm: Introduce pc_curr Peter Maydell
2019-08-16 13:16 ` [Qemu-devel] [PULL 08/29] target/arm: Introduce read_pc Peter Maydell
2019-08-16 13:16 ` [Qemu-devel] [PULL 09/29] target/arm: Introduce add_reg_for_lit Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 10/29] target/arm: Remove redundant s->pc & ~1 Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 11/29] target/arm: Replace s->pc with s->base.pc_next Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 12/29] target/arm: Replace offset with pc in gen_exception_insn Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 13/29] target/arm: Replace offset with pc in gen_exception_internal_insn Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 14/29] target/arm: Remove offset argument to gen_exception_bkpt_insn Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 15/29] target/arm: Use unallocated_encoding for aarch32 Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 16/29] target/arm: Remove helper_double_saturate Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 17/29] target/arm/cpu64: Ensure kvm really supports aarch64=off Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 18/29] target/arm/cpu: Ensure we can use the pmu with kvm Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 19/29] target/arm/helper: zcr: Add build bug next to value range assumption Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 20/29] target/arm/cpu: Use div-round-up to determine predicate register array size Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 21/29] target/arm/kvm64: Fix error returns Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 22/29] target/arm/kvm64: Move the get/put of fpsimd registers out Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 23/29] target/arm: Use tcg_gen_extract_i32 for shifter_out_im Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 24/29] target/arm: Use tcg_gen_deposit_i32 for PKHBT, PKHTB Peter Maydell
2019-08-16 13:17 ` Peter Maydell [this message]
2019-08-16 13:17 ` [Qemu-devel] [PULL 26/29] target/arm: Use ror32 instead of open-coding the operation Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 27/29] target/arm: Use tcg_gen_rotri_i32 for gen_swap_half Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 28/29] target/arm: Simplify SMMLA, SMMLAR, SMMLS, SMMLSR Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 29/29] target/arm: Use tcg_gen_extrh_i64_i32 to extract the high word Peter Maydell
2019-08-16 17:02 ` [Qemu-devel] [PULL 00/29] target-arm queue Peter Maydell

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