From 6eb3c9ee79c62459af61fecf304827cdec3dcdbc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alex=20Benn=C3=A9e?= <alex.bennee@linaro.org>
Date: Mon, 18 Nov 2019 20:45:38 -0500
Subject: [PATCH] fpu: use min/max values from stdint.h for integral overflow

Remove some more use of LIT64 while making the meaning more clear. We
also avoid the need of casts as the results by definition fit into the
return type.

Backports commit 2c217da0fc9f1127bda804e2a500b8138b02c581 from qemu
---
 qemu/fpu/softfloat.c | 32 +++++++++++++++-----------------
 1 file changed, 15 insertions(+), 17 deletions(-)

diff --git a/qemu/fpu/softfloat.c b/qemu/fpu/softfloat.c
index 5c4d21f5..513a3a0d 100644
--- a/qemu/fpu/softfloat.c
+++ b/qemu/fpu/softfloat.c
@@ -3362,7 +3362,7 @@ static int32_t roundAndPackInt32(flag zSign, uint64_t absZ, float_status *status
     if ( zSign ) z = - z;
     if ( ( absZ>>32 ) || ( z && ( ( z < 0 ) ^ zSign ) ) ) {
         float_raise(float_flag_invalid, status);
-        return zSign ? (int32_t) 0x80000000 : 0x7FFFFFFF;
+        return zSign ? INT32_MIN : INT32_MAX;
     }
     if (roundBits) {
         status->float_exception_flags |= float_flag_inexact;
@@ -3422,9 +3422,7 @@ static int64_t roundAndPackInt64(flag zSign, uint64_t absZ0, uint64_t absZ1,
     if ( z && ( ( z < 0 ) ^ zSign ) ) {
  overflow:
         float_raise(float_flag_invalid, status);
-        return
-              zSign ? (int64_t) LIT64( 0x8000000000000000 )
-            : LIT64( 0x7FFFFFFFFFFFFFFF );
+        return zSign ? INT64_MIN : INT64_MAX;
     }
     if (absZ1) {
         status->float_exception_flags |= float_flag_inexact;
@@ -3475,7 +3473,7 @@ static int64_t roundAndPackUint64(flag zSign, uint64_t absZ0,
         ++absZ0;
         if (absZ0 == 0) {
             float_raise(float_flag_invalid, status);
-            return LIT64(0xFFFFFFFFFFFFFFFF);
+            return UINT64_MAX;
         }
         absZ0 &= ~(((uint64_t)(absZ1<<1) == 0) & roundNearestEven);
     }
@@ -5497,9 +5495,9 @@ int64_t floatx80_to_int64(floatx80 a, float_status *status)
         if ( shiftCount ) {
             float_raise(float_flag_invalid, status);
             if (!aSign || floatx80_is_any_nan(a)) {
-                return LIT64( 0x7FFFFFFFFFFFFFFF );
+                return INT64_MAX;
             }
-            return (int64_t) LIT64( 0x8000000000000000 );
+            return INT64_MIN;
         }
         aSigExtra = 0;
     }
@@ -5540,10 +5538,10 @@ int64_t floatx80_to_int64_round_to_zero(floatx80 a, float_status *status)
         if ( ( a.high != 0xC03E ) || aSig ) {
             float_raise(float_flag_invalid, status);
             if ( ! aSign || ( ( aExp == 0x7FFF ) && aSig ) ) {
-                return LIT64( 0x7FFFFFFFFFFFFFFF );
+                return INT64_MAX;
             }
         }
-        return (int64_t) LIT64( 0x8000000000000000 );
+        return INT64_MIN;
     }
     else if ( aExp < 0x3FFF ) {
         if (aExp | aSig) {
@@ -6602,7 +6600,7 @@ int32_t float128_to_int32_round_to_zero(float128 a, float_status *status)
     if ( ( z < 0 ) ^ aSign ) {
  invalid:
         float_raise(float_flag_invalid, status);
-        return aSign ? (int32_t) 0x80000000 : 0x7FFFFFFF;
+        return aSign ? INT32_MIN : INT32_MAX;
     }
     if ( ( aSig0<<shiftCount ) != savedASig ) {
         status->float_exception_flags |= float_flag_inexact;
@@ -6641,9 +6639,9 @@ int64_t float128_to_int64(float128 a, float_status *status)
                       && ( aSig1 || ( aSig0 != LIT64( 0x0001000000000000 ) ) )
                     )
                ) {
-                return LIT64( 0x7FFFFFFFFFFFFFFF );
+                return INT64_MAX;
             }
-            return (int64_t) LIT64( 0x8000000000000000 );
+            return INT64_MIN;
         }
         shortShift128Left( aSig0, aSig1, - shiftCount, &aSig0, &aSig1 );
     }
@@ -6689,10 +6687,10 @@ int64_t float128_to_int64_round_to_zero(float128 a, float_status *status)
             else {
                 float_raise(float_flag_invalid, status);
                 if ( ! aSign || ( ( aExp == 0x7FFF ) && ( aSig0 | aSig1 ) ) ) {
-                    return LIT64( 0x7FFFFFFFFFFFFFFF );
+                    return INT64_MAX;
                 }
             }
-            return (int64_t) LIT64( 0x8000000000000000 );
+            return INT64_MIN;
         }
         z = ( aSig0<<shiftCount ) | ( aSig1>>( ( - shiftCount ) & 63 ) );
         if ( (uint64_t) ( aSig1<<shiftCount ) ) {
@@ -6743,19 +6741,19 @@ uint64_t float128_to_uint64(float128 a, float_status *status)
     if (aSign && (aExp > 0x3FFE)) {
         float_raise(float_flag_invalid, status);
         if (float128_is_any_nan(a)) {
-            return LIT64(0xFFFFFFFFFFFFFFFF);
+            return UINT64_MAX;
         } else {
             return 0;
         }
     }
     if (aExp) {
-        aSig0 |= LIT64(0x0001000000000000);
+        aSig0 |= UINT64_C(0x0001000000000000);
     }
     shiftCount = 0x402F - aExp;
     if (shiftCount <= 0) {
         if (0x403E < aExp) {
             float_raise(float_flag_invalid, status);
-            return LIT64(0xFFFFFFFFFFFFFFFF);
+            return UINT64_MAX;
         }
         shortShift128Left(aSig0, aSig1, -shiftCount, &aSig0, &aSig1);
     } else {