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authorRichard Henderson <rth@twiddle.net>2010-01-07 10:07:35 -0800
committerAurelien Jarno <aurelien@aurel32.net>2010-02-06 17:14:24 +0100
commita38e609c46e751f30277db6b3c07a3321c5c1d2a (patch)
tree87a79017dbca243e720fd89c4a850740b6ea498b
parentfd7a446f162768c044b3bf3844f7605eeef351af (diff)
tcg: document double-word support opcodes.
The internal opcodes brcond2, add2, sub2, mulu2 were undocumented. Place these in a new section that clearly indicates that they are not to be emitted by translators. Signed-off-by: Richard Henderson <rth@twiddle.net> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
-rw-r--r--tcg/README23
1 files changed, 23 insertions, 0 deletions
diff --git a/tcg/README b/tcg/README
index e672258faf..3d6c170efe 100644
--- a/tcg/README
+++ b/tcg/README
@@ -323,6 +323,29 @@ st32_i64 t0, t1, offset
write(t0, t1 + offset)
Write 8, 16, 32 or 64 bits to host memory.
+********* 64-bit target on 32-bit host support
+
+The following opcodes are internal to TCG. Thus they are to be implemented by
+32-bit host code generators, but are not to be emitted by guest translators.
+They are emitted as needed by inline functions within "tcg-op.h".
+
+* brcond2_i32 cond, t0_low, t0_high, t1_low, t1_high, label
+
+Similar to brcond, except that the 64-bit values T0 and T1
+are formed from two 32-bit arguments.
+
+* add2_i32 t0_low, t0_high, t1_low, t1_high, t2_low, t2_high
+* sub2_i32 t0_low, t0_high, t1_low, t1_high, t2_low, t2_high
+
+Similar to add/sub, except that the 64-bit inputs T1 and T2 are
+formed from two 32-bit arguments, and the 64-bit output T0
+is returned in two 32-bit outputs.
+
+* mulu2_i32 t0_low, t0_high, t1, t2
+
+Similar to mul, except two 32-bit (unsigned) inputs T1 and T2 yielding
+the full 64-bit product T0. The later is returned in two 32-bit outputs.
+
********* QEMU specific operations
* tb_exit t0