Patchwork [v4,23/33] tcg-aarch64: Use ORRI in tcg_out_movi

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Submitter Richard Henderson
Date Sept. 14, 2013, 9:54 p.m.
Message ID <1379195690-6509-24-git-send-email-rth@twiddle.net>
Download mbox | patch
Permalink /patch/274973/
State New
Headers show

Comments

Richard Henderson - Sept. 14, 2013, 9:54 p.m.
The subset of logical immediates that we support is quite quick to test,
and such constants are quite common to want to load.

Signed-off-by: Richard Henderson <rth@twiddle.net>
---
 tcg/aarch64/tcg-target.c | 9 +++++++++
 1 file changed, 9 insertions(+)

Patch

diff --git a/tcg/aarch64/tcg-target.c b/tcg/aarch64/tcg-target.c
index cecda05..9effee7 100644
--- a/tcg/aarch64/tcg-target.c
+++ b/tcg/aarch64/tcg-target.c
@@ -573,6 +573,15 @@  static void tcg_out_movi(TCGContext *s, TCGType type, TCGReg rd,
         type = TCG_TYPE_I32;
     }
 
+    /* Check for bitfield immediates.  For the benefit of 32-bit quantities,
+       use the sign-extended value.  That lets us match rotated values such
+       as 0xff0000ff with the same 64-bit logic matching 0xffffffffff0000ff.
+       The truncation happens inside tcg_fmt_Rdn_limm.  */
+    if (is_limm(svalue)) {
+        tcg_fmt_Rdn_limm(s, INSN_ORRI, type, rd, TCG_REG_XZR, svalue);
+        return;
+    }
+
     /* Would it take fewer insns to begin with MOVN?  For the value and its
        inverse, count the number of 16-bit lanes that are 0.  For the benefit
        of 32-bit quantities, compare the zero-extended normal value vs the