x86: optimize left-shift-by-1

These can be replaced by adds when acting on a register operand.

While for the scalar forms there's no gain in encoding size, ADD
generally has higher throughput than SHL. EFLAGS set by ADD are a
superset of those set by SHL (AF in particular is undefined there).

For the SIMD cases the transformation also reduced code size, by
eliminating the 1-byte immediate from the resulting encoding. Note
that this transformation is not applied by gcc13 (according to my
observations), so would - as of now - even improve compiler generated
code.

1 files changed, 24 insertions, 24 deletions

diff --git a/opcodes/i386-tbl.h b/opcodes/i386-tbl.h
index 38ccd1d..ac75d27 100644
--- a/opcodes/i386-tbl.h
+++ b/opcodes/i386-tbl.h
@@ -4036,7 +4036,7 @@ static const insn_template i386_optab[] =
 	  0, 0, 0, 0, 1, 0 } } } },
   { MN_sal, 0xd0, 3, SPACE_EVEXMAP4, 4,
     { 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0,
-      0, 0, 0, 0, 3, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+      0, 0, 0, 0, 3, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0,
       1, 0 },
     { { 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0 } },
     { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
@@ -4048,7 +4048,7 @@ static const insn_template i386_optab[] =
 	  0, 0, 0, 0, 0, 0 } } } },
   { MN_sal, 0xd0, 2, SPACE_BASE, 4,
     { 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0,
-      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0,
       0, 0 },
     { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
     { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
@@ -4058,7 +4058,7 @@ static const insn_template i386_optab[] =
 	  0, 0, 0, 0, 1, 0 } } } },
   { MN_sal, 0xd0, 2, SPACE_EVEXMAP4, 4,
     { 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0,
-      0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0,
       1, 0 },
     { { 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0 } },
     { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
@@ -4132,7 +4132,7 @@ static const insn_template i386_optab[] =
 	  0, 0, 0, 0, 1, 0 } } } },
   { MN_sal, 0xd0, 1, SPACE_BASE, 4,
     { 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0,
-      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0,
       0, 0 },
     { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
     { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
@@ -4140,7 +4140,7 @@ static const insn_template i386_optab[] =
 	  0, 0, 0, 0, 1, 0 } } } },
   { MN_shl, 0xd0, 3, SPACE_EVEXMAP4, 4,
     { 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0,
-      0, 0, 0, 0, 3, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+      0, 0, 0, 0, 3, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0,
       1, 0 },
     { { 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0 } },
     { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
@@ -4152,7 +4152,7 @@ static const insn_template i386_optab[] =
 	  0, 0, 0, 0, 0, 0 } } } },
   { MN_shl, 0xd0, 2, SPACE_BASE, 4,
     { 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0,
-      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0,
       0, 0 },
     { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
     { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
@@ -4162,7 +4162,7 @@ static const insn_template i386_optab[] =
 	  0, 0, 0, 0, 1, 0 } } } },
   { MN_shl, 0xd0, 2, SPACE_EVEXMAP4, 4,
     { 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0,
-      0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0,
       1, 0 },
     { { 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0 } },
     { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
@@ -4236,7 +4236,7 @@ static const insn_template i386_optab[] =
 	  0, 0, 0, 0, 1, 0 } } } },
   { MN_shl, 0xd0, 1, SPACE_BASE, 4,
     { 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0,
-      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0,
       0, 0 },
     { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
     { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
@@ -10974,7 +10974,7 @@ static const insn_template i386_optab[] =
 	  0, 0, 0, 0, 0, 0 } } } },
   { MN_psllw, 0x71, 2, SPACE_0F, 6,
     { 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0,
-      0, 0, 0, 1, 3, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1,
+      0, 0, 0, 1, 3, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1,
       0, 0 },
     { { 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0 } },
     { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
@@ -10984,7 +10984,7 @@ static const insn_template i386_optab[] =
 	  1, 0, 0, 0, 0, 0 } } } },
   { MN_psllw, 0x71, 2, SPACE_0F, 6,
     { 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0,
-      0, 0, 0, 0, 3, 1, 1, 0, 1, 2, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0,
+      0, 0, 0, 0, 3, 1, 1, 0, 1, 2, 0, 0, 0, 0, 4, 1, 0, 0, 0, 0,
       0, 0 },
     { { 35, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0 } },
     { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
@@ -10994,7 +10994,7 @@ static const insn_template i386_optab[] =
 	  1, 0, 0, 0, 0, 0 } } } },
   { MN_psllw, 0x71, 2, SPACE_0F, 6,
     { 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0,
-      0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+      0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0,
       0, 0 },
     { { 17, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
     { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
@@ -11004,7 +11004,7 @@ static const insn_template i386_optab[] =
 	  1, 0, 0, 0, 0, 0 } } } },
   { MN_psllw, 0x71, 2, SPACE_0F, 6,
     { 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0,
-      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0,
       0, 0 },
     { { 15, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
     { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
@@ -11044,7 +11044,7 @@ static const insn_template i386_optab[] =
 	  0, 0, 0, 0, 0, 0 } } } },
   { MN_pslld, 0x72 | 0, 2, SPACE_0F, 6,
     { 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0,
-      0, 0, 0, 1, 3, 1, 1, 0, 1, 2, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0,
+      0, 0, 0, 1, 3, 1, 1, 0, 1, 2, 0, 0, 0, 0, 4, 1, 0, 0, 0, 0,
       0, 0 },
     { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
     { { 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0 } },
@@ -11054,7 +11054,7 @@ static const insn_template i386_optab[] =
 	  1, 0, 0, 0, 0, 0 } } } },
   { MN_pslld, 0x72 | 0, 2, SPACE_0F, 6,
     { 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0,
-      0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+      0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0,
       0, 0 },
     { { 17, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
     { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
@@ -11064,7 +11064,7 @@ static const insn_template i386_optab[] =
 	  1, 0, 0, 0, 0, 0 } } } },
   { MN_pslld, 0x72 | 0, 2, SPACE_0F, 6,
     { 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0,
-      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0,
       0, 0 },
     { { 15, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
     { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
@@ -11114,7 +11114,7 @@ static const insn_template i386_optab[] =
 	  0, 0, 0, 0, 0, 0 } } } },
   { MN_psllq, 0x72 | 1, 2, SPACE_0F, 6,
     { 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0,
-      0, 0, 0, 1, 3, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1,
+      0, 0, 0, 1, 3, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1,
       0, 0 },
     { { 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0 } },
     { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
@@ -11124,7 +11124,7 @@ static const insn_template i386_optab[] =
 	  1, 0, 0, 0, 0, 0 } } } },
   { MN_psllq, 0x72 | 1, 2, SPACE_0F, 6,
     { 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0,
-      0, 0, 0, 0, 3, 2, 1, 0, 1, 2, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0,
+      0, 0, 0, 0, 3, 2, 1, 0, 1, 2, 0, 0, 0, 0, 4, 1, 0, 0, 0, 0,
       0, 0 },
     { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0 } },
     { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
@@ -11134,7 +11134,7 @@ static const insn_template i386_optab[] =
 	  1, 0, 0, 0, 0, 0 } } } },
   { MN_psllq, 0x72 | 1, 2, SPACE_0F, 6,
     { 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0,
-      0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+      0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0,
       0, 0 },
     { { 17, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
     { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
@@ -28476,7 +28476,7 @@ static const insn_template i386_optab[] =
 	  1, 1, 0, 0, 0, 0 } } } },
   { MN_vpslld, 0x72 | 0, 3, SPACE_0F, 6,
     { 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0,
-      0, 0, 0, 1, 3, 3, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1,
+      0, 0, 0, 1, 3, 3, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1,
       0, 0 },
     { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
     { { 30, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0 } },
@@ -28512,7 +28512,7 @@ static const insn_template i386_optab[] =
 	  1, 1, 1, 0, 0, 0 } } } },
   { MN_vpslld, 0x72 | 0, 3, SPACE_0F, 6,
     { 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0,
-      0, 0, 0, 0, 3, 1, 1, 0, 0, 5, 1, 3, 0, 0, 7, 0, 0, 0, 0, 0,
+      0, 0, 0, 0, 3, 1, 1, 0, 0, 5, 1, 3, 0, 0, 7, 1, 0, 0, 0, 0,
       0, 0 },
     { { 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0 } },
     { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
@@ -28524,7 +28524,7 @@ static const insn_template i386_optab[] =
 	  1, 1, 1, 0, 0, 0 } } } },
   { MN_vpsllq, 0x72 | 1, 3, SPACE_0F, 6,
     { 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0,
-      0, 0, 0, 1, 3, 3, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1,
+      0, 0, 0, 1, 3, 3, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1,
       0, 0 },
     { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
     { { 30, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0 } },
@@ -28560,7 +28560,7 @@ static const insn_template i386_optab[] =
 	  1, 1, 1, 0, 0, 0 } } } },
   { MN_vpsllq, 0x72 | 1, 3, SPACE_0F, 6,
     { 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0,
-      0, 0, 0, 0, 3, 2, 1, 0, 0, 5, 1, 4, 0, 0, 7, 0, 0, 0, 0, 0,
+      0, 0, 0, 0, 3, 2, 1, 0, 0, 5, 1, 4, 0, 0, 7, 1, 0, 0, 0, 0,
       0, 0 },
     { { 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0 } },
     { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
@@ -28596,7 +28596,7 @@ static const insn_template i386_optab[] =
 	  1, 1, 1, 0, 0, 0 } } } },
   { MN_vpsllw, 0x71, 3, SPACE_0F, 6,
     { 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0,
-      0, 0, 0, 1, 3, 3, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1,
+      0, 0, 0, 1, 3, 3, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1,
       0, 0 },
     { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
     { { 30, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0 } },
@@ -28620,7 +28620,7 @@ static const insn_template i386_optab[] =
 	  1, 1, 0, 0, 0, 0 } } } },
   { MN_vpsllw, 0x71, 3, SPACE_0F, 6,
     { 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0,
-      0, 0, 0, 0, 3, 3, 1, 0, 0, 5, 1, 0, 0, 0, 7, 0, 0, 0, 0, 0,
+      0, 0, 0, 0, 3, 3, 1, 0, 0, 5, 1, 0, 0, 0, 7, 1, 0, 0, 0, 0,
       0, 0 },
     { { 35, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },
     { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } },