From d8def4abd185c430d7649be9347778612c296871 Mon Sep 17 00:00:00 2001
From: Justin Bogner <mail@justinbogner.com>
Date: Fri, 4 Dec 2015 02:14:34 +0000
Subject: [PATCH] IR: Use format_hex instead of handrolling the conversion. NFC

Cleans up some very old code in AsmWriter's WriteConstantInternal.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254688 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/IR/AsmWriter.cpp | 64 ++++++++++++--------------------------------
 1 file changed, 17 insertions(+), 47 deletions(-)

diff --git a/lib/IR/AsmWriter.cpp b/lib/IR/AsmWriter.cpp
index cb9a792c598..fae1ebee5f2 100644
--- a/lib/IR/AsmWriter.cpp
+++ b/lib/IR/AsmWriter.cpp
@@ -39,6 +39,7 @@
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/Dwarf.h"
 #include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/Format.h"
 #include "llvm/Support/FormattedStream.h"
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Support/raw_ostream.h"
@@ -1137,15 +1138,12 @@ static void WriteConstantInternal(raw_ostream &Out, const Constant *CV,
       // x86, so we must not use these types.
       static_assert(sizeof(double) == sizeof(uint64_t),
                     "assuming that double is 64 bits!");
-      char Buffer[40];
       APFloat apf = CFP->getValueAPF();
       // Floats are represented in ASCII IR as double, convert.
       if (!isDouble)
         apf.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
                           &ignored);
-      Out << "0x" <<
-              utohex_buffer(uint64_t(apf.bitcastToAPInt().getZExtValue()),
-                            Buffer+40);
+      Out << format_hex(apf.bitcastToAPInt().getZExtValue(), 0, /*Upper=*/true);
       return;
     }
 
@@ -1153,60 +1151,32 @@ static void WriteConstantInternal(raw_ostream &Out, const Constant *CV,
     // These appear as a magic letter identifying the type, then a
     // fixed number of hex digits.
     Out << "0x";
-    // Bit position, in the current word, of the next nibble to print.
-    int shiftcount;
-
+    APInt API = CFP->getValueAPF().bitcastToAPInt();
     if (&CFP->getValueAPF().getSemantics() == &APFloat::x87DoubleExtended) {
       Out << 'K';
-      // api needed to prevent premature destruction
-      APInt api = CFP->getValueAPF().bitcastToAPInt();
-      const uint64_t* p = api.getRawData();
-      uint64_t word = p[1];
-      shiftcount = 12;
-      int width = api.getBitWidth();
-      for (int j=0; j<width; j+=4, shiftcount-=4) {
-        unsigned int nibble = (word>>shiftcount) & 15;
-        if (nibble < 10)
-          Out << (unsigned char)(nibble + '0');
-        else
-          Out << (unsigned char)(nibble - 10 + 'A');
-        if (shiftcount == 0 && j+4 < width) {
-          word = *p;
-          shiftcount = 64;
-          if (width-j-4 < 64)
-            shiftcount = width-j-4;
-        }
-      }
+      Out << format_hex_no_prefix(API.getHiBits(16).getZExtValue(), 4,
+                                  /*Upper=*/true);
+      Out << format_hex_no_prefix(API.getLoBits(64).getZExtValue(), 16,
+                                  /*Upper=*/true);
       return;
     } else if (&CFP->getValueAPF().getSemantics() == &APFloat::IEEEquad) {
-      shiftcount = 60;
       Out << 'L';
+      Out << format_hex_no_prefix(API.getLoBits(64).getZExtValue(), 16,
+                                  /*Upper=*/true);
+      Out << format_hex_no_prefix(API.getHiBits(64).getZExtValue(), 16,
+                                  /*Upper=*/true);
     } else if (&CFP->getValueAPF().getSemantics() == &APFloat::PPCDoubleDouble) {
-      shiftcount = 60;
       Out << 'M';
+      Out << format_hex_no_prefix(API.getLoBits(64).getZExtValue(), 16,
+                                  /*Upper=*/true);
+      Out << format_hex_no_prefix(API.getHiBits(64).getZExtValue(), 16,
+                                  /*Upper=*/true);
     } else if (&CFP->getValueAPF().getSemantics() == &APFloat::IEEEhalf) {
-      shiftcount = 12;
       Out << 'H';
+      Out << format_hex_no_prefix(API.getZExtValue(), 4,
+                                  /*Upper=*/true);
     } else
       llvm_unreachable("Unsupported floating point type");
-    // api needed to prevent premature destruction
-    APInt api = CFP->getValueAPF().bitcastToAPInt();
-    const uint64_t* p = api.getRawData();
-    uint64_t word = *p;
-    int width = api.getBitWidth();
-    for (int j=0; j<width; j+=4, shiftcount-=4) {
-      unsigned int nibble = (word>>shiftcount) & 15;
-      if (nibble < 10)
-        Out << (unsigned char)(nibble + '0');
-      else
-        Out << (unsigned char)(nibble - 10 + 'A');
-      if (shiftcount == 0 && j+4 < width) {
-        word = *(++p);
-        shiftcount = 64;
-        if (width-j-4 < 64)
-          shiftcount = width-j-4;
-      }
-    }
     return;
   }
 
-- 
2.34.1