8248901: Signed immediate support in .../share/assembler.hpp is broken

Patric Hedlin · Patric Hedlin · commit 3e0dc6888329 · 2020-07-06T21:29:51.000+02:00
Reviewed-by: neliasso, kvn, thartmann
diff --git a/src/hotspot/cpu/arm/arm.ad b/src/hotspot/cpu/arm/arm.ad
@@ -216,7 +216,7 @@ int ConstantTable::calculate_table_base_offset() const {
   // flds, fldd: 8-bit  offset multiplied by 4: +/- 1024
   // ldr, ldrb : 12-bit offset:                 +/- 4096
   if (!Assembler::is_simm10(offset)) {
-    offset = Assembler::min_simm10();
+    offset = Assembler::min_simm10;
   }
   return offset;
 }
diff --git a/src/hotspot/share/asm/assembler.hpp b/src/hotspot/share/asm/assembler.hpp
@@ -299,28 +299,29 @@ class AbstractAssembler : public ResourceObj  {
   void emit_double( jdouble x)                                  { code_section()->emit_double(x); }
   void emit_address(address x)                                  { code_section()->emit_address(x); }
 
-  // min and max values for signed immediate ranges
-  static int min_simm(int nbits) { return -(intptr_t(1) << (nbits - 1))    ; }
-  static int max_simm(int nbits) { return  (intptr_t(1) << (nbits - 1)) - 1; }
-
-  // Define some:
-  static int min_simm10() { return min_simm(10); }
-  static int min_simm13() { return min_simm(13); }
-  static int min_simm16() { return min_simm(16); }
-
-  // Test if x is within signed immediate range for nbits
-  static bool is_simm(intptr_t x, int nbits) { return min_simm(nbits) <= x && x <= max_simm(nbits); }
-
-  // Define some:
-  static bool is_simm5( intptr_t x) { return is_simm(x, 5 ); }
-  static bool is_simm8( intptr_t x) { return is_simm(x, 8 ); }
-  static bool is_simm10(intptr_t x) { return is_simm(x, 10); }
-  static bool is_simm11(intptr_t x) { return is_simm(x, 11); }
-  static bool is_simm12(intptr_t x) { return is_simm(x, 12); }
-  static bool is_simm13(intptr_t x) { return is_simm(x, 13); }
-  static bool is_simm16(intptr_t x) { return is_simm(x, 16); }
-  static bool is_simm26(intptr_t x) { return is_simm(x, 26); }
-  static bool is_simm32(intptr_t x) { return is_simm(x, 32); }
+  enum { min_simm10 = -512 };
+
+  // Test if x is within signed immediate range for width.
+  static bool is_simm(int64_t x, uint w) {
+    precond(1 < w && w < 64);
+    int64_t limes = INT64_C(1) << (w - 1);
+    return -limes <= x && x < limes;
+  }
+
+  static bool is_simm8(int64_t x) { return is_simm(x, 8); }
+  static bool is_simm9(int64_t x) { return is_simm(x, 9); }
+  static bool is_simm10(int64_t x) { return is_simm(x, 10); }
+  static bool is_simm16(int64_t x) { return is_simm(x, 16); }
+  static bool is_simm32(int64_t x) { return is_simm(x, 32); }
+
+  // Test if x is within unsigned immediate range for width.
+  static bool is_uimm(uint64_t x, uint w) {
+    precond(0 < w && w < 64);
+    uint64_t limes = UINT64_C(1) << w;
+    return x < limes;
+  }
+
+  static bool is_uimm12(uint64_t x) { return is_uimm(x, 12); }
 
   // Accessors
   CodeSection*  code_section() const   { return _code_section; }

Original file line number	Diff line number	Diff line change
`@@ -216,7 +216,7 @@ int ConstantTable::calculate_table_base_offset() const {`
`216`	`216`	`// flds, fldd: 8-bit offset multiplied by 4: +/- 1024`
`217`	`217`	`// ldr, ldrb : 12-bit offset: +/- 4096`
`218`	`218`	`if (!Assembler::is_simm10(offset)) {`
`219`		`- offset = Assembler::min_simm10();`
	`219`	`+ offset = Assembler::min_simm10;`
`220`	`220`	`}`
`221`	`221`	`return offset;`
`222`	`222`	`}`