Signed vs unsigned lower halves of powerpc fixups are now handled by having two

assembler directives, ha16() and has16(), for the upper half; has16() applies
the sign adjustment. .powerpcfixup is now gone, as we generate the relocation
in ha*() instead. Add special logic to the linker for undoing and redoing the
sign adjustment when reading/writing fixups. Tests still pass.

mach/powerpc/as/mach1.c

@@ -3,3 +3,7 @@
  * $State$
  */
 
+#include <stdbool.h>
+
+extern quad emit_ha(struct expr_t* expr, bool is_signed);
+extern quad emit_lo(struct expr_t* expr);

mach/powerpc/as/mach2.c

@@ -85,7 +85,7 @@
 %token <y_word> OP_LI32
 
 %token <y_word> OP_POWERPC_FIXUP
-%token <y_word> OP_HI OP_LO
+%token <y_word> OP_HA OP_HAS OP_LO
 
 /* Other token types */
 

mach/powerpc/as/mach3.c

@@ -102,8 +102,8 @@
 0,     OP_LA,                 0,                                       "la",
 0,     OP_LA,                 0,                                       "li",
 0,     OP_RS_RA_RA_C,         31<<26 | 444<<1,                         "mr",
-0,     OP_POWERPC_FIXUP,      0,                                       ".powerpcfixup",
+0,     OP_HA,                 0,                                       "ha16",
-0,     OP_HI,                 0,                                       "ha16",
+0,     OP_HAS,                0,                                       "has16",
 0,     OP_LO,                 0,                                       "lo16",
 
 /* Branch processor instructions (page 20) */

mach/powerpc/as/mach4.c

@@ -60,7 +60,6 @@ operation
 	| OP_LIA               lia                        { emit4($1 | $2); }
 	| OP_LIL               lil                        { emit4($1 | $2); }
 	| OP_LI32              li32                       /* emitted in subrule */
-	| OP_POWERPC_FIXUP     powerpcfixup               /* emitted in subrule */
 	;
 
 c
@@ -76,32 +75,9 @@ e16
 			serror("16-bit value out of range");
 		$$ = (uint16_t) $1;
 	}
-	| OP_HI ASC_LPAR expr ASC_RPAR
+	| OP_HA ASC_LPAR expr ASC_RPAR           { $$ = emit_ha(&$3, false); }
-	{
+	| OP_HAS ASC_LPAR expr ASC_RPAR          { $$ = emit_ha(&$3, true); }
-		/* If this is a symbol reference, discard the symbol and keep only the
+	| OP_LO ASC_LPAR expr ASC_RPAR           { $$ = emit_lo(&$3); }
-		 * offset part. */
-		quad type = $3.typ & S_TYP;
-		quad val = $3.val;
-
-		/* If the assembler stored a symbol for relocation later, we need to
-		 * abandon it (because we're not going to generate a relocation). */
-		if (type != S_ABS)
-			relonami = 0;
-
-		$$ = ((quad)val) >> 16;
-	}
-	| OP_LO ASC_LPAR expr ASC_RPAR
-	{
-		quad type = $3.typ & S_TYP;
-		quad val = $3.val;
-
-		/* If the assembler stored a symbol for relocation later, we need to
-		 * abandon it (because we're not going to generate a relocation). */
-		if (type != S_ABS)
-			relonami = 0;
-
-		$$ = val & 0xffff;
-	}
 	;
 
 u8

mach/powerpc/as/mach5.c

@@ -1,4 +1,38 @@
-/*
+
- * $Source$
+quad emit_ha(struct expr_t* expr, bool is_signed)
- * $State$
+{
+    /* If this is a symbol reference, discard the symbol and keep only the
+        * offset part. */
+    quad type = expr->typ & S_TYP;
+    quad val = expr->val;
+    uint16_t hi = val >> 16;
+    uint16_t lo = val & 0xffff;
+
+    if (type != S_ABS)
+		newrelo(expr->typ, RELOPPC | FIXUPFLAGS);
+
+    /* If the low half of this relocation is going to be a memory operation,
+     * then it'll be treated as a signed value. That means that values greater
+     * than 0x7fff will cause the high word to have 1 subtracted from it; so
+     * we apply an adjustment here.
      */
+
+    if (is_signed && (lo > 0x7fff))
+        hi++;
+
+    return hi;
+}
+
+quad emit_lo(struct expr_t* expr)
+{
+    quad type = expr->typ & S_TYP;
+    quad val = expr->val;
+
+    /* If the assembler stored a symbol for relocation later, we need to
+     * abandon it (because the relocation was generated by emit_ha). */
+
+    if (type != S_ABS)
+        relonami = 0;
+
+    return val & 0xffff;
+}

mach/powerpc/ncg/table

@@ -175,7 +175,8 @@ TOKENS
 /* Primitives */
 
 	LABEL              = { ADDR adr; }            4    adr.
-	LABEL_OFFSET_HI    = { ADDR adr; }            4    "ha16[" adr "]".
+	LABEL_OFFSET_HA    = { ADDR adr; }            4    "ha16[" adr "]".
+	LABEL_OFFSET_HAS   = { ADDR adr; }            4    "has16[" adr "]".
 	LABEL_OFFSET_LO    = { ADDR adr; }            4    "lo16[" adr "]".
 	LOCAL              = { INT off; }             4.
 
@@ -285,7 +286,7 @@ INSTRUCTIONS
   add             GPR:wo, GPR:ro, GPR:ro.
   addX "add."     GPR:wo, GPR:ro, GPR:ro.
   addi            GPR:wo, GPR:ro, CONST:ro.
-  addis           GPR:wo, GPR:ro, CONST+LABEL_OFFSET_HI:ro.
+  addis           GPR:wo, GPR:ro, CONST+LABEL_OFFSET_HA+LABEL_OFFSET_HAS:ro.
   and             GPR:wo, GPR:ro, GPR:ro.
   andc            GPR:wo, GPR:ro, GPR:ro.
   andiX  "andi."  GPR:wo:cc, GPR:ro, CONST:ro.
@@ -370,7 +371,6 @@ INSTRUCTIONS
   xori            GPR:wo, GPR:ro, CONST:ro.
   xoris           GPR:wo, GPR:ro, CONST:ro.
 
-  fixup   ".powerpcfixup" LABEL:ro.
   comment "!"             LABEL:ro cost(0, 0).
 
 
@@ -408,8 +408,7 @@ MOVES
 	from LABEL to GPR
 		gen
 			COMMENT("move LABEL->GPR")
-			fixup {LABEL, %1.adr}
+			addis %2, R0, {LABEL_OFFSET_HA, %1.adr}
-			addis %2, R0, {LABEL_OFFSET_HI, %1.adr}
 			ori %2, %2, {LABEL_OFFSET_LO, %1.adr}
 
 /* Sign extension */
@@ -1150,8 +1149,7 @@ PATTERNS
 		with LABEL
 			uses REG
 			gen
-				fixup {LABEL, %1.adr}
+				addis %a, R0, {LABEL_OFFSET_HAS, %1.adr}
-				addis %a, R0, {LABEL_OFFSET_HI, %1.adr}
 				lwz %a, {GPRINDIRECT_OFFSET_LO, %a, %1.adr}
 			yields %a
 		with GPR

util/led/const.h

@@ -4,8 +4,6 @@
  */
 /* $Id$ */
 
-typedef int		bool;
-
 #define FALSE		0
 #define TRUE		1
 

util/led/debug.h

@@ -17,3 +17,5 @@ extern int DEB;
 
 extern int Verbose;
 #define verbose(s, a1, a2, a3, a4)	(Verbose && do_verbose(s, a1, a2, a3, a4))
+
+extern void fatal(char* format, ...);

util/led/relocate.c

@@ -9,6 +9,7 @@ static char rcsid[] = "$Id$";
 #include <stdlib.h>
 #include <stdio.h>
 #include <stdint.h>
+#include <stdbool.h>
 #include <assert.h>
 #include "out.h"
 #include "const.h"
@@ -104,6 +105,24 @@ static uint32_t get_vc4_valu(char* addr)
 	assert(0 && "unrecognised VC4 instruction");
 }
 
+static bool is_powerpc_memory_op(uint32_t opcode)
+{
+	/* Tests for any PowerPC memory indirection instruction where the payload
+	 * is a *signed* 16-bit value. */
+	switch ((opcode & 0xfc000000) >> 26)
+	{
+		case 34: /* lbz */
+		case 40: /* lhz */
+		case 32: /* lwz */
+		case 38: /* stb */
+		case 44: /* sth */
+		case 36: /* stw */
+			return true;
+	}
+
+	return false;
+}
+
 /* PowerPC fixups are complex as we need to patch up to the next two
  * instructions in one of several different ways, depending on what the
  * instructions area.
@@ -125,8 +144,23 @@ static uint32_t get_powerpc_valu(char* addr, uint16_t type)
 		/* addis / ori instruction pair */
 		return ((opcode1 & 0xffff) << 16) | (opcode2 & 0xffff);
 	}
+	else if (((opcode1 & 0xfc1f0000) == 0x3c000000) &&
+	         is_powerpc_memory_op(opcode2))
+	{
+		/* addis / memoryop instruction pair */
+		uint16_t hi = opcode1 & 0xffff;
+		uint16_t lo = opcode2 & 0xffff;
 
-	assert(0 && "unrecognised PowerPC instruction");
+		/* Undo the sign adjustment (see mach/powerpc/as/mach5.c). */
+
+		if (lo > 0x7fff)
+			hi--;
+
+		return ((hi << 16) | lo);
+	}
+
+	fatal("Don't know how to read from PowerPC fixup on instructions 0x%08x+0x%08x",
+		opcode1, opcode2);
 }
 
 /*
@@ -269,8 +303,25 @@ static void put_powerpc_valu(char* addr, uint32_t value, uint16_t type)
 		write4((opcode1 & 0xffff0000) | hi, addr+0, type);
 		write4((opcode2 & 0xffff0000) | lo, addr+4, type);
 	}
+	else if (((opcode1 & 0xfc1f0000) == 0x3c000000) &&
+	         is_powerpc_memory_op(opcode2))
+	{
+		/* addis / memoryop instruction pair */
+		uint16_t hi = value >> 16;
+		uint16_t lo = value & 0xffff;
+
+		/* Apply the sign adjustment (see mach/powerpc/as/mach5.c). */
+
+		if (lo > 0x7fff)
+			hi++;
+
+		write4((opcode1 & 0xffff0000) | hi, addr+0, type);
+		write4((opcode2 & 0xffff0000) | lo, addr+4, type);
+	}
+
 	else
-		assert(0 && "unrecognised PowerPC instruction");
+		fatal("Don't know how to write a PowerPC fixup to instructions 0x%08x+0x%08x",
+			opcode1, opcode2);
 }
 
 /*