On 11/09/2016 06:30 PM, Laurent Vivier wrote:
+ /* create [src:X:..] */
+
+ tcg_gen_deposit_i32(t0, QREG_CC_X, src, 1, size);
+ tcg_gen_shli_i32(t0, t0, 31 - size);
+
+ /* rotate */
+
+ tcg_gen_rotl_i32(t0, t0, shift);
+
+ /* result is [src:..:src:X] */
+
+ tcg_gen_andi_i32(X, t0, 1);
+ tcg_gen_shri_i32(t0, t0, 1);
I don't see how this is supposed to work. If you form [src:x:...], and rotate
by 0, then X gets garbage. Of course, you're actually forming [0:src:x]. But
for a rol of 2, the lsb of src gets 0's instead of the msb of src.
If you want to use a 32-bit rotate here, you have to (1) reduce the rotate by
modulo size + 1 and (2) form [src:...:src:x]. E.g.
tcg_gen_deposit_i32(t0, Q_REG_CC_X, src, 32 - size, size);
tcg_gen_deposit_i32(t0, t0, src, 1, size);