[builtins] Support architectures with 16-bit int in __ashlti3, __ashrti3 and __lshrti3

[Ka-Ka]

Summary

The amount to shift should be specified by the int type not a 32-bit integer
type.

This patch change the functions for 128-bit shifts in compiler-rt the same way
as was done for 64-bit shifts in D78662.

The README.txt is updated with the shift builtins signatures from this patch and D78662.

[Ka-Ka]

git-clang-format

[efriedma]

LGTM

compiler-rt/lib/builtins/README.txt

 typedef  int32_t si_int;
 typedef uint32_t su_int;
 
 typedef  int64_t di_int;
 typedef uint64_t du_int;
 
 // Integral bit manipulation
 
-di_int __ashldi3(di_int a, si_int b);      // a << b
-ti_int __ashlti3(ti_int a, si_int b);      // a << b
+di_int __ashldi3(di_int a, int b);         // a << b
+ti_int __ashlti3(ti_int a, int b);         // a << b
 
-di_int __ashrdi3(di_int a, si_int b);      // a >> b  arithmetic (sign fill)
-ti_int __ashrti3(ti_int a, si_int b);      // a >> b  arithmetic (sign fill)
-di_int __lshrdi3(di_int a, si_int b);      // a >> b  logical    (zero fill)
-ti_int __lshrti3(ti_int a, si_int b);      // a >> b  logical    (zero fill)
+di_int __ashrdi3(di_int a, int b);         // a >> b  arithmetic (sign fill)
+ti_int __ashrti3(ti_int a, int b);         // a >> b  arithmetic (sign fill)
+di_int __lshrdi3(di_int a, int b);         // a >> b  logical    (zero fill)
+ti_int __lshrti3(ti_int a, int b);         // a >> b  logical    (zero fill)
 
 int __clzsi2(si_int a);  // count leading zeros
 int __clzdi2(di_int a);  // count leading zeros
 int __clzti2(ti_int a);  // count leading zeros
 int __ctzsi2(si_int a);  // count trailing zeros
 int __ctzdi2(di_int a);  // count trailing zeros
 int __ctzti2(ti_int a);  // count trailing zeros
 

compiler-rt/lib/builtins/ashlti3.c

 #include "int_lib.h"
 
 #ifdef CRT_HAS_128BIT
 
 // Returns: a << b
 
 // Precondition:  0 <= b < bits_in_tword
 
-COMPILER_RT_ABI ti_int __ashlti3(ti_int a, si_int b) {
+COMPILER_RT_ABI ti_int __ashlti3(ti_int a, int b) {
   const int bits_in_dword = (int)(sizeof(di_int) * CHAR_BIT);
   twords input;
   twords result;
   input.all = a;
   if (b & bits_in_dword) /* bits_in_dword <= b < bits_in_tword */ {
     result.s.low = 0;
     result.s.high = input.s.low << (b - bits_in_dword);
   } else /* 0 <= b < bits_in_dword */ {

compiler-rt/lib/builtins/ashrti3.c

 #include "int_lib.h"
 
 #ifdef CRT_HAS_128BIT
 
 // Returns: arithmetic a >> b
 
 // Precondition:  0 <= b < bits_in_tword
 
-COMPILER_RT_ABI ti_int __ashrti3(ti_int a, si_int b) {
+COMPILER_RT_ABI ti_int __ashrti3(ti_int a, int b) {
   const int bits_in_dword = (int)(sizeof(di_int) * CHAR_BIT);
   twords input;
   twords result;
   input.all = a;
   if (b & bits_in_dword) /* bits_in_dword <= b < bits_in_tword */ {
     // result.s.high = input.s.high < 0 ? -1 : 0
     result.s.high = input.s.high >> (bits_in_dword - 1);
     result.s.low = input.s.high >> (b - bits_in_dword);

compiler-rt/lib/builtins/lshrti3.c

 #include "int_lib.h"
 
 #ifdef CRT_HAS_128BIT
 
 // Returns: logical a >> b
 
 // Precondition:  0 <= b < bits_in_tword
 
-COMPILER_RT_ABI ti_int __lshrti3(ti_int a, si_int b) {
+COMPILER_RT_ABI ti_int __lshrti3(ti_int a, int b) {
   const int bits_in_dword = (int)(sizeof(di_int) * CHAR_BIT);
   utwords input;
   utwords result;
   input.all = a;
   if (b & bits_in_dword) /* bits_in_dword <= b < bits_in_tword */ {
     result.s.high = 0;
     result.s.low = input.s.high >> (b - bits_in_dword);
   } else /* 0 <= b < bits_in_dword */ {

compiler-rt/test/builtins/Unit/ashlti3_test.c

 // RUN: %clang_builtins %s %librt -o %t && %run %t
 // REQUIRES: librt_has_ashlti3
 // REQUIRES: int128
 
 #include "int_lib.h"
 #include <stdio.h>
 
 #ifdef CRT_HAS_128BIT
 
 // Returns: a << b
 
 // Precondition:  0 <= b < bits_in_tword
 
-COMPILER_RT_ABI ti_int __ashlti3(ti_int a, si_int b);
+COMPILER_RT_ABI ti_int __ashlti3(ti_int a, int b);
 
-int test__ashlti3(ti_int a, si_int b, ti_int expected)
+int test__ashlti3(ti_int a, int b, ti_int expected)
 {
     ti_int x = __ashlti3(a, b);
     if (x != expected)
     {
         twords at;
         at.all = a;
         twords bt;
         bt.all = b;

compiler-rt/test/builtins/Unit/ashrti3_test.c

 // RUN: %clang_builtins %s %librt -o %t && %run %t
 // REQUIRES: librt_has_ashrti3
 // REQUIRES: int128
 
 #include "int_lib.h"
 #include <stdio.h>
 
 #ifdef CRT_HAS_128BIT
 
 // Returns: arithmetic a >> b
 
 // Precondition:  0 <= b < bits_in_tword
 
-COMPILER_RT_ABI ti_int __ashrti3(ti_int a, si_int b);
+COMPILER_RT_ABI ti_int __ashrti3(ti_int a, int b);
 
-int test__ashrti3(ti_int a, si_int b, ti_int expected)
+int test__ashrti3(ti_int a, int b, ti_int expected)
 {
     ti_int x = __ashrti3(a, b);
     if (x != expected)
     {
         twords at;
         at.all = a;
         twords xt;
         xt.all = x;

compiler-rt/test/builtins/Unit/lshrti3_test.c

 // RUN: %clang_builtins %s %librt -o %t && %run %t
 // REQUIRES: librt_has_lshrti3
 // REQUIRES: int128
 
 #include "int_lib.h"
 #include <stdio.h>
 
 #ifdef CRT_HAS_128BIT
 
 // Returns: logical a >> b
 
 // Precondition:  0 <= b < bits_in_dword
 
-COMPILER_RT_ABI ti_int __lshrti3(ti_int a, si_int b);
+COMPILER_RT_ABI ti_int __lshrti3(ti_int a, int b);
 
-int test__lshrti3(ti_int a, si_int b, ti_int expected)
+int test__lshrti3(ti_int a, int b, ti_int expected)
 {
     ti_int x = __lshrti3(a, b);
     if (x != expected)
     {
         twords at;
         at.all = a;
         twords xt;
         xt.all = x;