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authorAurelien Jarno <aurelien@aurel32.net>2013-09-03 08:27:38 +0200
committerRichard Henderson <rth@twiddle.net>2014-02-17 10:12:28 -0600
commitf096dc96188378bc2bcd80683490ca386b0c1683 (patch)
treed17d247a76ec1d516625016848607b2886a914de /tcg/optimize.c
parent3031244b01492528fd7b5e46b23eeb2124dc780a (diff)
downloadfocaccia-qemu-f096dc96188378bc2bcd80683490ca386b0c1683.tar.gz
focaccia-qemu-f096dc96188378bc2bcd80683490ca386b0c1683.zip
tcg/optimize: improve known-zero bits for 32-bit ops
The shl_i32 op might set some bits of the unused 32 high bits of the
mask. Fix that by clearing the unused 32 high bits for all 32-bit ops
except load/store which operate on tl values.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Diffstat (limited to 'tcg/optimize.c')
-rw-r--r--tcg/optimize.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/tcg/optimize.c b/tcg/optimize.c
index 7838be2c50..1cf017aab8 100644
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -783,6 +783,12 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
             break;
         }
 
+        /* 32-bit ops (non 64-bit ops and non load/store ops) generate 32-bit
+           results */
+        if (!(tcg_op_defs[op].flags & (TCG_OPF_CALL_CLOBBER | TCG_OPF_64BIT))) {
+            mask &= 0xffffffffu;
+        }
+
         if (mask == 0) {
             assert(def->nb_oargs == 1);
             s->gen_opc_buf[op_index] = op_to_movi(op);