[llvm-commits] CVS: reopt/lib/TraceCache/InstrUtils.cpp

[Brian Gaeke]

Changes in directory reopt/lib/TraceCache:

InstrUtils.cpp updated: 1.17 -> 1.18

---
Log message:

Reorganize and document isCallInstr().
Reorganize getCallTarget().
Document getUndepJumpInstr() and rename its operands.
Edit getDepJumpInstr()'s comment.


---
Diffs of the changes:  (+31 -18)

Index: reopt/lib/TraceCache/InstrUtils.cpp
diff -u reopt/lib/TraceCache/InstrUtils.cpp:1.17 reopt/lib/TraceCache/InstrUtils.cpp:1.18
--- reopt/lib/TraceCache/InstrUtils.cpp:1.17	Mon Apr 26 14:47:33 2004
+++ reopt/lib/TraceCache/InstrUtils.cpp	Mon Apr 26 15:02:59 2004
@@ -49,6 +49,13 @@
   return (instr & 0xd1c00000) == 0x00c00000;
 }
 
+/// isCallInstr - Returns true iff instr encodes a CALL instruction.
+/// See SPARCv9 manual, section A.8.
+///
+bool isCallInstr (unsigned int instr) {
+  return (instr & 0xc0000000) == 0x40000000;
+}
+
 //===----------------------------------------------------------------------===//
 //===----- Instructions for extracting SPARCv9 branch target addresses ----===//
 
@@ -82,6 +89,12 @@
   return (oldAdd+4*(((b&2097152)==2097152)?(0xffffffffffff0000ULL|((b&3145728)>>6)|(b&16383)):(((b&3145728)>>6)|(b&16383))));
 }
 
+uint64_t getCallTarget(unsigned int y, uint64_t oldAdd){
+  return oldAdd + 4 * (((y&0x20000000) == 0x20000000)
+                       ? (0xffffffffc0000000ULL | (y & 0x3fffffff))
+                       : (y & 0x3fffffff));
+}
+
 //===----------------------------------------------------------------------===//
 //===----- Instructions for extracting SPARCv9 branch target addresses ----===//
 
@@ -99,21 +112,31 @@
   }
 } 
 
-unsigned int getUndepJumpInstr(unsigned int a, uint64_t to, uint64_t pc){
-  if(to>pc)
-    assert((to-pc)/4<262144 && "Can't fit target!");
+/// getUndepJumpInstr - Returns a PC-relative branch instruction from address
+/// FROM to address TO of the same conditionality (BA, BN, BNE, BE, BG...) as
+/// INSTR.  INSTR must be a BPcc or FBPfcc instruction (branch on integer
+/// condition codes with prediction and annul bits), and FROM must be its
+/// address in memory.
+///
+unsigned int getUndepJumpInstr(unsigned int instr, uint64_t to, uint64_t from) {
+  if(to>from)
+    assert((to-from)/4<262144 && "Can't fit target!");
   else 
-    assert((pc-to)/4<262144 && "Can't fit target!");
+    assert((from-to)/4<262144 && "Can't fit target!");
       
-  unsigned int diff = (((to-pc)/4)&0x3ffff);
-  unsigned int sgn = ((to < pc) ? (1 << 21) : 0);
-  return ((a&0xfff80000U)|diff|sgn);
+  // Compute new 19-bit PC-relative branch target.
+  unsigned int diff = (((to-from)/4)&0x3ffff);
+  unsigned int sgn = ((to < from) ? (1 << 21) : 0);
+
+  // Mask out the old branch target, OR in the new one, and return it.
+  return ((instr&0xfff80000U)|diff|sgn);
 }
 
 /// getDepJumpInstr - Returns a PC-relative branch instruction from address
 /// FROM to address TO of the same conditionality (BA, BN, BNE, BE, BG...) as
 /// INSTR.  INSTR must be a Bicc or FBfcc instruction (branch on integer
-/// condition codes with no prediction), and FROM must be its address in memory.
+/// condition codes with no prediction bits), and FROM must be its address in
+/// memory.
 ///
 unsigned int getDepJumpInstr(unsigned int instr, uint64_t to, uint64_t from) {
   if(to>from)
@@ -147,16 +170,6 @@
 
 //TODO: put assert to check branch destinations!
 //TODO: Take out sign bit in branch instr
-
-bool isCallInstr(unsigned int a){
-  return ((a & 0xc0000000) == 0x40000000);
-}
-
-uint64_t getCallTarget(unsigned int y, uint64_t oldAdd){
-  return oldAdd + 4 * (((y&0x20000000) == 0x20000000)
-                       ? (0xffffffffc0000000ULL | (y & 0x3fffffff))
-                       : (y & 0x3fffffff));
-}
 
 // pc is the "from" address
 unsigned int getCallInstr(uint64_t to , uint64_t pc){