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[Qemu-devel] [PATCH v2 06/10] target-arm: fix neon vsri, vshl and vsli o


From: juha . riihimaki
Subject: [Qemu-devel] [PATCH v2 06/10] target-arm: fix neon vsri, vshl and vsli ops
Date: Sat, 24 Oct 2009 15:19:05 +0300

From: Juha Riihimäki <address@hidden>

Shift by immediate value is incorrectly overwritten by a temporary
variable in the processing of NEON vsri, vshl and vsli instructions.
This patch has been revised to also include a fix for the special
case where the code would previously try to shift an integer value
over 31 bits left/right.

Signed-off-by: Juha Riihimäki <address@hidden>
---
 target-arm/translate.c |   32 ++++++++++++++++++--------------
 1 files changed, 18 insertions(+), 14 deletions(-)

diff --git a/target-arm/translate.c b/target-arm/translate.c
index d1e2ed2..9e924d4 100644
--- a/target-arm/translate.c
+++ b/target-arm/translate.c
@@ -4098,7 +4098,7 @@ static int disas_neon_data_insn(CPUState * env, 
DisasContext *s, uint32_t insn)
     int pairwise;
     int u;
     int n;
-    uint32_t imm;
+    uint32_t imm, mask;
     TCGv tmp, tmp2, tmp3, tmp4, tmp5;
     TCGv_i64 tmp64;
 
@@ -4626,31 +4626,35 @@ static int disas_neon_data_insn(CPUState * env, 
DisasContext *s, uint32_t insn)
                             switch (size) {
                             case 0:
                                 if (op == 4)
-                                    imm = 0xff >> -shift;
+                                    mask = 0xff >> -shift;
                                 else
-                                    imm = (uint8_t)(0xff << shift);
-                                imm |= imm << 8;
-                                imm |= imm << 16;
+                                    mask = (uint8_t)(0xff << shift);
+                                mask |= mask << 8;
+                                mask |= mask << 16;
                                 break;
                             case 1:
                                 if (op == 4)
-                                    imm = 0xffff >> -shift;
+                                    mask = 0xffff >> -shift;
                                 else
-                                    imm = (uint16_t)(0xffff << shift);
-                                imm |= imm << 16;
+                                    mask = (uint16_t)(0xffff << shift);
+                                mask |= mask << 16;
                                 break;
                             case 2:
-                                if (op == 4)
-                                    imm = 0xffffffffu >> -shift;
-                                else
-                                    imm = 0xffffffffu << shift;
+                                if (shift < -31 || shift > 31) {
+                                    mask = 0;
+                                } else {
+                                    if (op == 4)
+                                        mask = 0xffffffffu >> -shift;
+                                    else
+                                        mask = 0xffffffffu << shift;
+                                }
                                 break;
                             default:
                                 abort();
                             }
                             tmp2 = neon_load_reg(rd, pass);
-                            tcg_gen_andi_i32(tmp, tmp, imm);
-                            tcg_gen_andi_i32(tmp2, tmp2, ~imm);
+                            tcg_gen_andi_i32(tmp, tmp, mask);
+                            tcg_gen_andi_i32(tmp2, tmp2, ~mask);
                             tcg_gen_or_i32(tmp, tmp, tmp2);
                             dead_tmp(tmp2);
                         }
-- 
1.6.5





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