From: Julian Seward <jseward@acm.org>
Date: Mon, 24 Apr 2017 10:57:05 +0000 (+0000)
Subject: widen_z_16_to_64, widen_z_8_to_64: generate less stupid code.
X-Git-Tag: svn/VALGRIND_3_13_0^2~31
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=18cb98e216f25a0fd3089ac5077cfdcabee0e696;p=thirdparty%2Fvalgrind.git

widen_z_16_to_64, widen_z_8_to_64: generate less stupid code.


git-svn-id: svn://svn.valgrind.org/vex/trunk@3353
---

diff --git a/VEX/priv/host_arm64_isel.c b/VEX/priv/host_arm64_isel.c
index 07ce87a834..11bcb9055d 100644
--- a/VEX/priv/host_arm64_isel.c
+++ b/VEX/priv/host_arm64_isel.c
@@ -298,10 +298,9 @@ static HReg widen_s_16_to_64 ( ISelEnv* env, HReg src )
    a new register, and return the new register. */
 static HReg widen_z_16_to_64 ( ISelEnv* env, HReg src )
 {
-   HReg      dst = newVRegI(env);
-   ARM64RI6* n48 = ARM64RI6_I6(48);
-   addInstr(env, ARM64Instr_Shift(dst, src, n48, ARM64sh_SHL));
-   addInstr(env, ARM64Instr_Shift(dst, dst, n48, ARM64sh_SHR));
+   HReg      dst  = newVRegI(env);
+   ARM64RIL* mask = ARM64RIL_I13(1, 0, 15); /* encodes 0xFFFF */
+   addInstr(env, ARM64Instr_Logic(dst, src, mask, ARM64lo_AND));
    return dst;
 }
 
@@ -329,10 +328,9 @@ static HReg widen_s_8_to_64 ( ISelEnv* env, HReg src )
 
 static HReg widen_z_8_to_64 ( ISelEnv* env, HReg src )
 {
-   HReg      dst = newVRegI(env);
-   ARM64RI6* n56 = ARM64RI6_I6(56);
-   addInstr(env, ARM64Instr_Shift(dst, src, n56, ARM64sh_SHL));
-   addInstr(env, ARM64Instr_Shift(dst, dst, n56, ARM64sh_SHR));
+   HReg      dst  = newVRegI(env);
+   ARM64RIL* mask = ARM64RIL_I13(1, 0, 7); /* encodes 0xFF */
+   addInstr(env, ARM64Instr_Logic(dst, src, mask, ARM64lo_AND));
    return dst;
 }