[mips][msa] Range adjustment for ldi_b builtin function operand

Reasoning behind this change was allowing the function to accept all values
from range [-128, 255] since all of them can be encoded in an 8bit wide
value.
This differs from the prior state where only range [-128, 127] was accepted,
where values were assumed to be signed, whereas now the actual
interpretation of the immediate is deferred to the consumer as required.

Patch by Stefan Maksimovic.

Differential Revision: https://reviews.llvm.org/D31082

llvm-svn: 299229

clang/lib/Sema/SemaChecking.cpp

@@ -1640,7 +1640,7 @@ bool Sema::CheckMipsBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
   case Mips::BI__builtin_msa_sldi_d: i = 2; l = 0; u = 1; break;
   // Memory offsets and immediate loads.
   // These intrinsics take a signed 10 bit immediate.
-  case Mips::BI__builtin_msa_ldi_b: i = 0; l = -128; u = 127; break;
+  case Mips::BI__builtin_msa_ldi_b: i = 0; l = -128; u = 255; break;
   case Mips::BI__builtin_msa_ldi_h:
   case Mips::BI__builtin_msa_ldi_w:
   case Mips::BI__builtin_msa_ldi_d: i = 0; l = -512; u = 511; break;

clang/test/CodeGen/builtins-mips-msa-error.c

@@ -119,7 +119,7 @@ void test(void) {
   v4i32_r = __msa_ld_w(&v4i32_a, 512);               // expected-error {{argument should be a value from -512 to 511}}
   v2i64_r = __msa_ld_d(&v2i64_a, 512);               // expected-error {{argument should be a value from -512 to 511}}
 
-  v16i8_r = __msa_ldi_b(512);                        // expected-error {{argument should be a value from -512 to 511}}
+  v16i8_r = __msa_ldi_b(256);                        // expected-error {{argument should be a value from -128 to 255}}
   v8i16_r = __msa_ldi_h(512);                        // expected-error {{argument should be a value from -512 to 511}}
   v4i32_r = __msa_ldi_w(512);                        // expected-error {{argument should be a value from -512 to 511}}
   v2i64_r = __msa_ldi_d(512);                        // expected-error {{argument should be a value from -512 to 511}}
@@ -310,7 +310,7 @@ void test(void) {
   v4i32_r = __msa_ld_w(&v4i32_a, -513);              // expected-error {{argument should be a value from -512 to 511}}
   v2i64_r = __msa_ld_d(&v2i64_a, -513);              // expected-error {{argument should be a value from -512 to 511}}
 
-  v16i8_r = __msa_ldi_b(-513);                       // expected-error {{argument should be a value from -512 to 511}}
+  v16i8_r = __msa_ldi_b(-129);                       // expected-error {{argument should be a value from -128 to 255}}
   v8i16_r = __msa_ldi_h(-513);                       // expected-error {{argument should be a value from -512 to 511}}
   v4i32_r = __msa_ldi_w(-513);                       // expected-error {{argument should be a value from -512 to 511}}
   v2i64_r = __msa_ldi_d(-513);                       // expected-error {{argument should be a value from -512 to 511}}

clang/test/CodeGen/builtins-mips-msa.c

@@ -526,6 +526,8 @@ void test(void) {
   v2i64_r = __msa_ld_d(&v2i64_a, 96); // CHECK: call <2  x i64> @llvm.mips.ld.d(
 
   v16i8_r = __msa_ldi_b(3); // CHECK: call <16 x i8>  @llvm.mips.ldi.b(
+  v16i8_r = __msa_ldi_b(-128); // CHECK: call <16 x i8>  @llvm.mips.ldi.b(
+  v16i8_r = __msa_ldi_b(255); // CHECK: call <16 x i8>  @llvm.mips.ldi.b(
   v8i16_r = __msa_ldi_h(3); // CHECK: call <8  x i16> @llvm.mips.ldi.h(
   v4i32_r = __msa_ldi_w(3); // CHECK: call <4  x i32> @llvm.mips.ldi.w(
   v2i64_r = __msa_ldi_d(3); // CHECK: call <2  x i64> @llvm.mips.ldi.d(