This is primarily Shreya's work from a few months back. I just fixed
the formatting, cobbled together the cover letter/ChangeLog.
We were looking to evaluate some changes from Artemiy that improve GCC's
ability to discover fusible instruction pairs. There was no good way to
get any static data out of the compiler about what kinds of fusions were
happening. Yea, you could grub around the .sched dumps looking for the
magic '+' annotation, then look around at the slim RTL representation
and make an educated guess about what fused. But boy that was inconvenient.
All we really needed was a quick note in the dump file that the target
hook found a fusion pair and what kind was discovered. That made it
easy to spot invalid fusions, evaluate the effectiveness of Artemiy's
work, write/discover testcases for existing fusions and implement new
fusions.
So from a codegen standpoint this is NFC, it only affects dump file output.
It's gone through the usual testing and I'll wait for pre-commit CI to
churn through it before moving forward.
Jeff
gcc/
* config/riscv/riscv.cc (riscv_macro_fusion_pair_p): Add basic
instrumentation to all cases where fusion is detected. Fix
minor formatting goofs found in the process.
diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
index 8fa1082f7c13..167e78d41ef4 100644
--- a/gcc/config/riscv/riscv.cc
+++ b/gcc/config/riscv/riscv.cc
@@ -10253,11 +10253,15 @@ riscv_macro_fusion_pair_p (rtx_insn *prev, rtx_insn
*curr)
&& CONST_INT_P (XEXP (SET_SRC (prev_set), 1))
&& CONST_INT_P (XEXP (SET_SRC (curr_set), 1))
&& INTVAL (XEXP (SET_SRC (prev_set), 1)) == 32
- && (( INTVAL (XEXP (SET_SRC (curr_set), 1)) == 32
- && riscv_fusion_enabled_p(RISCV_FUSE_ZEXTW) )
- || ( INTVAL (XEXP (SET_SRC (curr_set), 1)) < 32
- && riscv_fusion_enabled_p(RISCV_FUSE_ZEXTWS))))
- return true;
+ && ((INTVAL (XEXP (SET_SRC (curr_set), 1)) == 32
+ && riscv_fusion_enabled_p (RISCV_FUSE_ZEXTW) )
+ || (INTVAL (XEXP (SET_SRC (curr_set), 1)) < 32
+ && riscv_fusion_enabled_p (RISCV_FUSE_ZEXTWS))))
+ {
+ if (dump_file)
+ fprintf (dump_file, "RISCV_FUSE_ZEXTWS\n");
+ return true;
+ }
}
if (simple_sets_p && riscv_fusion_enabled_p (RISCV_FUSE_ZEXTH)
@@ -10278,7 +10282,11 @@ riscv_macro_fusion_pair_p (rtx_insn *prev, rtx_insn
*curr)
&& CONST_INT_P (XEXP (SET_SRC (curr_set), 1))
&& INTVAL (XEXP (SET_SRC (prev_set), 1)) == 48
&& INTVAL (XEXP (SET_SRC (curr_set), 1)) == 48)
- return true;
+ {
+ if (dump_file)
+ fprintf (dump_file,"RISCV_FUSE_ZEXTH\n");
+ return true;
+ }
}
if (simple_sets_p && riscv_fusion_enabled_p (RISCV_FUSE_LDINDEXED)
@@ -10297,7 +10305,11 @@ riscv_macro_fusion_pair_p (rtx_insn *prev, rtx_insn
*curr)
&& GET_CODE (SET_SRC (prev_set)) == PLUS
&& REG_P (XEXP (SET_SRC (prev_set), 0))
&& REG_P (XEXP (SET_SRC (prev_set), 1)))
- return true;
+ {
+ if (dump_file)
+ fprintf (dump_file, "RISCV_FUSE_LDINDEXED\n");
+ return true;
+ }
/* We are trying to match the following:
prev (add) == (set (reg:DI rD)
@@ -10313,7 +10325,11 @@ riscv_macro_fusion_pair_p (rtx_insn *prev, rtx_insn
*curr)
&& GET_CODE (SET_SRC (prev_set)) == PLUS
&& REG_P (XEXP (SET_SRC (prev_set), 0))
&& REG_P (XEXP (SET_SRC (prev_set), 1)))
- return true;
+ {
+ if (dump_file)
+ fprintf (dump_file, "RISCV_FUSE_LDINDEXED\n");
+ return true;
+ }
}
if (simple_sets_p && riscv_fusion_enabled_p (RISCV_FUSE_LDPREINCREMENT)
@@ -10332,7 +10348,11 @@ riscv_macro_fusion_pair_p (rtx_insn *prev, rtx_insn
*curr)
&& GET_CODE (SET_SRC (prev_set)) == PLUS
&& REG_P (XEXP (SET_SRC (prev_set), 0))
&& CONST_INT_P (XEXP (SET_SRC (prev_set), 1)))
- return true;
+ {
+ if (dump_file)
+ fprintf (dump_file, "RISCV_FUSE_LDPREINCREMENT\n");
+ return true;
+ }
}
if (simple_sets_p && riscv_fusion_enabled_p (RISCV_FUSE_LUI_ADDI)
@@ -10350,7 +10370,11 @@ riscv_macro_fusion_pair_p (rtx_insn *prev, rtx_insn
*curr)
&& (GET_CODE (SET_SRC (prev_set)) == HIGH
|| (CONST_INT_P (SET_SRC (prev_set))
&& LUI_OPERAND (INTVAL (SET_SRC (prev_set))))))
- return true;
+ {
+ if (dump_file)
+ fprintf (dump_file, "RISCV_FUSE_LUI_ADDI\n");
+ return true;
+ }
}
if (simple_sets_p && riscv_fusion_enabled_p (RISCV_FUSE_AUIPC_ADDI)
@@ -10372,7 +10396,11 @@ riscv_macro_fusion_pair_p (rtx_insn *prev, rtx_insn
*curr)
&& CONST_INT_P (XEXP (SET_SRC (curr_set), 1))
&& SMALL_OPERAND (INTVAL (XEXP (SET_SRC (curr_set), 1))))))
- return true;
+ {
+ if (dump_file)
+ fprintf (dump_file, "RISCV_FUSE_AUIPC_ADDI\n");
+ return true;
+ }
}
if (simple_sets_p && riscv_fusion_enabled_p (RISCV_FUSE_LUI_LD)
@@ -10392,14 +10420,22 @@ riscv_macro_fusion_pair_p (rtx_insn *prev, rtx_insn
*curr)
&& SCALAR_INT_MODE_P (GET_MODE (SET_DEST (curr_set)))
&& GET_CODE (XEXP (SET_SRC (curr_set), 0)) == PLUS
&& REGNO (XEXP (XEXP (SET_SRC (curr_set), 0), 0)) == prev_dest_regno)
- return true;
+ {
+ if (dump_file)
+ fprintf (dump_file, "RISCV_FUSE_LUI_LD\n");
+ return true;
+ }
if (GET_CODE (SET_SRC (prev_set)) == HIGH
&& MEM_P (SET_SRC (curr_set))
&& SCALAR_INT_MODE_P (GET_MODE (SET_DEST (curr_set)))
&& GET_CODE (XEXP (SET_SRC (curr_set), 0)) == LO_SUM
&& REGNO (XEXP (XEXP (SET_SRC (curr_set), 0), 0)) == prev_dest_regno)
- return true;
+ {
+ if (dump_file)
+ fprintf (dump_file, "RISCV_FUSE_LUI_LD\n");
+ return true;
+ }
if (GET_CODE (SET_SRC (prev_set)) == HIGH
&& (GET_CODE (SET_SRC (curr_set)) == SIGN_EXTEND
@@ -10409,7 +10445,11 @@ riscv_macro_fusion_pair_p (rtx_insn *prev, rtx_insn
*curr)
&& (GET_CODE (XEXP (XEXP (SET_SRC (curr_set), 0), 0)) == LO_SUM
&& (REGNO (XEXP (XEXP (XEXP (SET_SRC (curr_set), 0), 0), 0))
== prev_dest_regno)))
- return true;
+ {
+ if (dump_file)
+ fprintf (dump_file, "RISCV_FUSE_LUI_LD\n");
+ return true;
+ }
}
if (simple_sets_p && riscv_fusion_enabled_p (RISCV_FUSE_AUIPC_LD)
@@ -10425,7 +10465,11 @@ riscv_macro_fusion_pair_p (rtx_insn *prev, rtx_insn
*curr)
&& MEM_P (SET_SRC (curr_set))
&& SCALAR_INT_MODE_P (GET_MODE (SET_DEST (curr_set)))
&& GET_CODE (XEXP (SET_SRC (curr_set), 0)) == PLUS)
- return true;
+ {
+ if (dump_file)
+ fprintf (dump_file, "RISCV_FUSE_AUIPC_LD\n");
+ return true;
+ }
}
if (simple_sets_p && riscv_fusion_enabled_p (RISCV_FUSE_ALIGNED_STD))
@@ -10473,7 +10517,11 @@ riscv_macro_fusion_pair_p (rtx_insn *prev, rtx_insn
*curr)
lower offset. */
if ((INTVAL (offset_prev) % 16) == 0
&& (INTVAL (offset_prev) + 8 == INTVAL (offset_curr)))
- return true;
+ {
+ if (dump_file)
+ fprintf (dump_file, "RISCV_FUSE_ALIGNED_STD\n");
+ return true;
+ }
}
}
}
