Improved 32x32=64bit multiplication

[r15776]

diff --git a/ir/be/ia32/ia32_intrinsics.c b/ir/be/ia32/ia32_intrinsics.c
index cc7a607..859f6f3 100644 (file)
--- a/ir/be/ia32/ia32_intrinsics.c
+++ b/ir/be/ia32/ia32_intrinsics.c
@@ -437,23 +437,46 @@ static int map_Mul(ir_node *call, void *ctx) {
                h_res = t2 + t3
        */
 
                h_res = t2 + t3
        */
 

-       if (is_Shrs(a_h) && get_Shrs_left(a_h) == a_l &&
-               is_Shrs(b_h) && get_Shrs_left(b_h) == b_l) {
+       /* handle the often used case of 32x32=64 mul */
+       if (is_Shrs(a_h) && get_Shrs_left(a_h) == a_l) {

                ir_node *c1 = get_Shrs_right(a_h);
 
                ir_node *c1 = get_Shrs_right(a_h);
 

-               if (c1 == get_Shrs_right(b_h) && is_Const(c1)) {
+               if (is_Const(c1)) {

                        tarval *tv = get_Const_tarval(c1);
 
                        if (tarval_is_long(tv) && get_tarval_long(tv) == 31) {
                        tarval *tv = get_Const_tarval(c1);
 
                        if (tarval_is_long(tv) && get_tarval_long(tv) == 31) {

-                               /* it's a 32 * 32 = 64 signed multiplication */
-
-                               mul   = new_rd_ia32_l_IMul(dbg, irg, block, a_l, b_l);
-                               h_res = new_rd_Proj(dbg, irg, block, mul, l_mode, pn_ia32_l_Mul_EDX);
-                               l_res = new_rd_Proj(dbg, irg, block, mul, l_mode, pn_ia32_l_Mul_EAX);
-
-                               goto end;
+                               /* a is a sign extend */
+
+                               if (is_Shrs(b_h) && get_Shrs_left(b_h) == b_l && c1 == get_Shrs_right(b_h)) {
+                                       /* b is a sign extend: it's a 32 * 32 = 64 signed multiplication */
+                                       mul   = new_rd_ia32_l_IMul(dbg, irg, block, a_l, b_l);
+                                       h_res = new_rd_Proj(dbg, irg, block, mul, l_mode, pn_ia32_l_Mul_EDX);
+                                       l_res = new_rd_Proj(dbg, irg, block, mul, l_mode, pn_ia32_l_Mul_EAX);
+
+                                       goto end;
+                               }
+                               /* we rely here on Consts being on the right site */
+                               if (is_Const(b_h) && is_Const(b_l)) {
+                                       tarval *th = get_Const_tarval(b_h);
+                                       tarval *tl = get_Const_tarval(b_l);
+
+                                       if (tarval_is_long(th) && tarval_is_long(tl)) {
+                                               long h = get_tarval_long(th);
+                                               long l = get_tarval_long(tl);
+
+                                               if ((h == 0 && l >= 0) || (h == -1 && l < 0)) {
+                                                       /* b is a sign extended const */
+                                                       mul   = new_rd_ia32_l_IMul(dbg, irg, block, a_l, b_l);
+                                                       h_res = new_rd_Proj(dbg, irg, block, mul, l_mode, pn_ia32_l_Mul_EDX);
+                                                       l_res = new_rd_Proj(dbg, irg, block, mul, l_mode, pn_ia32_l_Mul_EAX);
+
+                                                       goto end;
+                                               }
+                                       }
+                               }

                        }
                }
                        }
                }

+

        }
 
        mul   = new_rd_ia32_l_Mul(dbg, irg, block, a_l, b_l);
        }
 
        mul   = new_rd_ia32_l_Mul(dbg, irg, block, a_l, b_l);