[committed,amdgcn] Fix regrename ICE

Message ID 5e2fdb33-f2e8-fe51-d7c8-736700bb6f43@codesourcery.com
State New
Headers show
Series
  • [committed,amdgcn] Fix regrename ICE
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Commit Message

Andrew Stubbs July 2, 2019, 12:02 p.m.
This patch fixes a regrename ICE that affects testcase 
gfortran.dg/optional_absent_4.f90.

The problem was that the save-restore pattern for the SCC register 
conflicted with the live value in that register. That is, it looked fine 
in the dump files and assembler output, but broken the assumptions about 
how RTX entries are shared in memory.

The fix is simply to hide the save-restore, for now. We end up with the 
same instruction sequence anyway.

Andrew Stubbs
Mentor Graphics / CodeSourcery

Patch

Fix amdgcn regrename ICE.

2019-07-02  Andrew Stubbs  <ams@codesourcery.com>

	gcc/
	* config/gcn/gcn.md (movdi_symbol_save_scc): Convert to define_insn
	with inlined save and restore.

diff --git a/gcc/config/gcn/gcn.md b/gcc/config/gcn/gcn.md
index 1f06d0bd5cc..7e5cf17629d 100644
--- a/gcc/config/gcn/gcn.md
+++ b/gcc/config/gcn/gcn.md
@@ -830,18 +830,36 @@ 
  [(set_attr "type" "mult")
   (set_attr "length" "32")])
 
-(define_insn_and_split "movdi_symbol_save_scc"
+(define_insn "movdi_symbol_save_scc"
  [(set (match_operand:DI 0 "nonimmediate_operand" "=Sg")
        (match_operand:DI 1 "general_operand" "Y"))
   (clobber (reg:BI CC_SAVE_REG))]
- "GET_CODE (operands[1]) == SYMBOL_REF || GET_CODE (operands[1]) == LABEL_REF
+ "(GET_CODE (operands[1]) == SYMBOL_REF || GET_CODE (operands[1]) == LABEL_REF)
   && (lra_in_progress || reload_completed)"
- "#"
- "reload_completed"
- [(set (reg:BI CC_SAVE_REG) (reg:BI SCC_REG))
-  (parallel [(set (match_dup 0) (match_dup 1))
-	     (clobber (reg:BI SCC_REG))])
-  (set (reg:BI SCC_REG) (reg:BI CC_SAVE_REG))])
+  {
+    /* !!! These sequences clobber CC_SAVE_REG.  */
+
+    if (SYMBOL_REF_P (operands[1])
+	&& SYMBOL_REF_WEAK (operands[1]))
+	return "; s_mov_b32\ts22, scc is not supported by the assembler.\;"
+	       ".long\t0xbe9600fd\;"
+	       "s_getpc_b64\t%0\;"
+	       "s_add_u32\t%L0, %L0, %1@gotpcrel32@lo+4\;"
+	       "s_addc_u32\t%H0, %H0, %1@gotpcrel32@hi+4\;"
+	       "s_load_dwordx2\t%0, %0\;"
+	       "s_cmpk_lg_u32\ts22, 0\;"
+	       "s_waitcnt\tlgkmcnt(0)";
+
+    return "; s_mov_b32\ts22, scc is not supported by the assembler.\;"
+	   ".long\t0xbe9600fd\;"
+	   "s_getpc_b64\t%0\;"
+	   "s_add_u32\t%L0, %L0, %1@rel32@lo+4\;"
+	   "s_addc_u32\t%H0, %H0, %1@rel32@hi+4\;"
+	   "s_cmpk_lg_u32\ts22, 0";
+  }
+ [(set_attr "type" "mult")
+  (set_attr "length" "40")])
+
 
 (define_insn "gcn_indirect_call"
   [(call (mem (match_operand:DI 0 "register_operand" "Sg"))