https://gcc.gnu.org/g:353bf917a996e5246e7aa0c4c223fc4359339626

commit r17-3848-g353bf917a996e5246e7aa0c4c223fc4359339626
Author: Haochen Jiang <[email protected]>
Date:   Wed Sep 2 16:38:42 2026 +0800

    Add tmm as fake register
    
    In legacy AMX, we use inline assembly for intrins since we are
    not doing tile register allocation. For ACE, we will try a different
    way.
    
    Although we are not doing tile register allocation for now since
    there is no convenient way for register spill, which is a must for
    register allocation, we are going to make it convenient for future
    implementation for potential register allocation. Thus, we will
    introduce a fake tmm register.
    
    We will use internal pattern instead of inline assembly wrapper
    to support ACE ISAs. This will help compiler know the dependency on
    insts. In this case, compiler will rely on users to pass tmm
    register number and do the register allocation themselves. Since in
    ACE, tmm is an accumulation unit rather than a calculation unit,
    allocation by user is acceptable.
    
    gcc/ChangeLog:
    
            * config/i386/i386.cc (regclass_map): Add tmm.
            (debugger64_register_map): Ditto.
            (debugger_register_map): Ditto. Also fix for APX r16-31.
            (svr4_debugger_register_map): Ditto.
            (ix86_conditional_register_usage): Enable tmm only when AMX
            or ACE exists.
            * config/i386/i386.h (FIXED_REGISTERS): Ditto.
            (CALL_USED_REGISTERS): Ditto.
            (REG_ALLOC_ORDER): Ditto.
            (HI_REGISTER_NAMES): Ditto.
            * config/i386/i386.md: Ditto.
    
    Co-authored-by: Dipesh Sharma <[email protected]>

Diff:
---
 gcc/config/i386/i386.cc | 30 +++++++++++++++++++++++++++---
 gcc/config/i386/i386.h  | 13 +++++++++----
 gcc/config/i386/i386.md |  3 ++-
 3 files changed, 38 insertions(+), 8 deletions(-)

diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
index 32d5a598c5af..9033cfce3b5f 100644
--- a/gcc/config/i386/i386.cc
+++ b/gcc/config/i386/i386.cc
@@ -179,6 +179,8 @@ enum reg_class const regclass_map[FIRST_PSEUDO_REGISTER] =
   GENERAL_REGS, GENERAL_REGS, GENERAL_REGS, GENERAL_REGS,
   GENERAL_REGS, GENERAL_REGS, GENERAL_REGS, GENERAL_REGS,
   GENERAL_REGS, GENERAL_REGS, GENERAL_REGS, GENERAL_REGS,
+  /* TMM fake register placeholder */
+  NO_REGS,
 };
 
 /* The "default" register map used in 32bit mode.  */
@@ -209,7 +211,14 @@ unsigned int const 
debugger_register_map[FIRST_PSEUDO_REGISTER] =
   INVALID_REGNUM, INVALID_REGNUM, INVALID_REGNUM, INVALID_REGNUM,
   INVALID_REGNUM, INVALID_REGNUM, INVALID_REGNUM, INVALID_REGNUM,
   /* Mask registers */
-  93, 94, 95, 96, 97, 98, 99, 100
+  93, 94, 95, 96, 97, 98, 99, 100,
+  /* APX r16-r31 */
+  INVALID_REGNUM, INVALID_REGNUM, INVALID_REGNUM, INVALID_REGNUM,
+  INVALID_REGNUM, INVALID_REGNUM, INVALID_REGNUM, INVALID_REGNUM,
+  INVALID_REGNUM, INVALID_REGNUM, INVALID_REGNUM, INVALID_REGNUM,
+  INVALID_REGNUM, INVALID_REGNUM, INVALID_REGNUM, INVALID_REGNUM,
+  /* TMM fake register placeholder */
+  INVALID_REGNUM,
 };
 
 /* The "default" register map used in 64bit mode.  */
@@ -239,7 +248,9 @@ unsigned int const 
debugger64_register_map[FIRST_PSEUDO_REGISTER] =
   118, 119, 120, 121, 122, 123, 124, 125,
   /* rex2 extend integer registers */
   130, 131, 132, 133, 134, 135, 136, 137,
-  138, 139, 140, 141, 142, 143, 144, 145
+  138, 139, 140, 141, 142, 143, 144, 145,
+  /* tmm fake register placeholder */
+  IGNORED_DWARF_REGNUM,
 };
 
 /* Define the register numbers to be used in Dwarf debugging information.
@@ -322,7 +333,14 @@ unsigned int const 
svr4_debugger_register_map[FIRST_PSEUDO_REGISTER] =
   INVALID_REGNUM, INVALID_REGNUM, INVALID_REGNUM, INVALID_REGNUM,
   INVALID_REGNUM, INVALID_REGNUM, INVALID_REGNUM, INVALID_REGNUM,
   /* Mask registers */
-  93, 94, 95, 96, 97, 98, 99, 100
+  93, 94, 95, 96, 97, 98, 99, 100,
+  /* APX r16-r31 */
+  INVALID_REGNUM, INVALID_REGNUM, INVALID_REGNUM, INVALID_REGNUM,
+  INVALID_REGNUM, INVALID_REGNUM, INVALID_REGNUM, INVALID_REGNUM,
+  INVALID_REGNUM, INVALID_REGNUM, INVALID_REGNUM, INVALID_REGNUM,
+  INVALID_REGNUM, INVALID_REGNUM, INVALID_REGNUM, INVALID_REGNUM,
+  /* TMM fake register placeholder */
+  INVALID_REGNUM,
 };
 
 /* Define parameter passing and return registers.  */
@@ -564,6 +582,12 @@ ix86_conditional_register_usage (void)
       for (i = FIRST_REX2_INT_REG; i <= LAST_REX2_INT_REG; i++)
        CLEAR_HARD_REG_BIT (accessible_reg_set, i);
     }
+
+  /* If AMX-TILE or ACEV1 is disabled, disable tmm registers.  */
+  if (! (TARGET_AMX_TILE || TARGET_ACEV1))
+    {
+      CLEAR_HARD_REG_BIT (accessible_reg_set, TMM_REGNUM);
+    }
 }
 
 /* Canonicalize a comparison from one we don't have to one we do have.  */
diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
index 26c3b73a50f9..f1bc63ab9815 100644
--- a/gcc/config/i386/i386.h
+++ b/gcc/config/i386/i386.h
@@ -1025,7 +1025,9 @@ extern const char *host_detect_local_cpu (int argc, const 
char **argv);
 /*  r16,  r17, r18, r19, r20, r21, r22, r23*/                  \
      0,   0,   0,   0,   0,   0,   0,   0,                     \
 /*  r24,  r25, r26, r27, r28, r29, r30, r31*/                  \
-     0,   0,   0,   0,   0,   0,   0,   0}                     \
+     0,   0,   0,   0,   0,   0,   0,   0,                     \
+/*  tmm*/                                                      \
+     1}                                                                \
 
 /* 1 for registers not available across function calls.
    These must include the FIXED_REGISTERS and also any
@@ -1066,7 +1068,9 @@ extern const char *host_detect_local_cpu (int argc, const 
char **argv);
 /*  r16,  r17, r18, r19, r20, r21, r22, r23*/                  \
      1,   1,   1,   1,   1,   1,   1,   1,                     \
 /*  r24,  r25, r26, r27, r28, r29, r30, r31*/                  \
-     1,   1,   1,   1,   1,   1,   1,   1}                     \
+     1,   1,   1,   1,   1,   1,   1,   1,                     \
+/*  tmm*/                                                      \
+     1}                                                                \
 
 /* Order in which to allocate registers.  Each register must be
    listed once, even those in FIXED_REGISTERS.  List frame pointer
@@ -1083,7 +1087,7 @@ extern const char *host_detect_local_cpu (int argc, const 
char **argv);
   32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,      \
   48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63,      \
   64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79,      \
-  80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91}
+  80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92}
 
 /* ADJUST_REG_ALLOC_ORDER is a macro which permits reg_alloc_order
    to be rearranged based on a particular function.  When using sse math,
@@ -2105,7 +2109,8 @@ do {                                                      
\
  "xmm28", "xmm29", "xmm30", "xmm31",                                   \
  "k0", "k1", "k2", "k3", "k4", "k5", "k6", "k7",                       \
  "r16", "r17", "r18", "r19", "r20", "r21", "r22", "r23",               \
- "r24", "r25", "r26", "r27", "r28", "r29", "r30", "r31" }
+ "r24", "r25", "r26", "r27", "r28", "r29", "r30", "r31",               \
+ "tmm"}
 
 #define REGISTER_NAMES HI_REGISTER_NAMES
 
diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index 5768a93d5b0d..6bbb6dbc31ea 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -508,7 +508,8 @@
    (R29_REG                    89)
    (R30_REG                    90)
    (R31_REG                    91)
-   (FIRST_PSEUDO_REG           92)
+   (TMM_REGNUM                 92)
+   (FIRST_PSEUDO_REG           93)
   ])
 
 ;; Insn callee abi index.

Reply via email to