[X86] early-ifcvt-remarks.ll - use i64 arithmetic to ensure ifcvt doesn't drop below threshold

Upcoming SimplifyDemandedBits support for CMOV will simplify the code and reduce the critical path below the threshold if we stick with i32 multiplies

Author: RKSimon

llvm/test/CodeGen/X86/early-ifcvt-remarks.ll

@@ -68,24 +68,24 @@ if.else:
   ret i32 %res
 }
 
-define i32 @mm3(i1 %pred, i32 %val, i32 %e1, i128 %e2, i128 %e3, i128 %e4, i128 %e5) {
+define i64 @mm3(i1 %pred, i64 %val, i64 %e1, i128 %e2, i128 %e3, i128 %e4, i128 %e5) {
 ; CHECK-LABEL: mm3:
 ; CHECK:       # %bb.0: # %entry
-; CHECK-NEXT:    movl %esi, %eax
+; CHECK-NEXT:    movq %rsi, %rax
 ; CHECK-NEXT:    testb $1, %dil
-; CHECK-NEXT:    movl %esi, %r10d
+; CHECK-NEXT:    movq %rsi, %r10
 ; CHECK-NEXT:    jne .LBB2_2
 ; CHECK-NEXT:  # %bb.1: # %if.false
 ; CHECK-NEXT:    movq {{[0-9]+}}(%rsp), %rsi
 ; CHECK-NEXT:    movq {{[0-9]+}}(%rsp), %rdi
-; CHECK-NEXT:    imull %edx, %edx
-; CHECK-NEXT:    movslq %edx, %r10
-; CHECK-NEXT:    movq %rcx, %rax
-; CHECK-NEXT:    movl %edx, %r9d
-; CHECK-NEXT:    mulq %r10
-; CHECK-NEXT:    imulq %r10, %r8
+; CHECK-NEXT:    imulq %rdx, %rdx
+; CHECK-NEXT:    movq %rdx, %r10
 ; CHECK-NEXT:    sarq $63, %r10
+; CHECK-NEXT:    movq %rcx, %rax
+; CHECK-NEXT:    movq %rdx, %r9
+; CHECK-NEXT:    mulq %rdx
 ; CHECK-NEXT:    imulq %rcx, %r10
+; CHECK-NEXT:    imulq %r9, %r8
 ; CHECK-NEXT:    addq %rdx, %r8
 ; CHECK-NEXT:    addq %r10, %r8
 ; CHECK-NEXT:    addq {{[0-9]+}}(%rsp), %rax
@@ -106,9 +106,9 @@ define i32 @mm3(i1 %pred, i32 %val, i32 %e1, i128 %e2, i128 %e3, i128 %e4, i128
 ; CHECK-NEXT:    orq %rdi, %r10
 ; CHECK-NEXT:    testb $64, %sil
 ; CHECK-NEXT:    cmovneq %rax, %r10
-; CHECK-NEXT:    movl %r9d, %eax
+; CHECK-NEXT:    movq %r9, %rax
 ; CHECK-NEXT:  .LBB2_2: # %if.endif
-; CHECK-NEXT:    addl %r10d, %eax
+; CHECK-NEXT:    addq %r10, %rax
 ; CHECK-NEXT:    retq
 entry:
   br i1 %pred, label %if.true, label %if.false
@@ -117,19 +117,19 @@ if.true:
   br label %if.endif
 
 if.false:
-  %f1 = mul i32 %e1, %e1
-  %f3 = sext i32 %f1 to i128
+  %f1 = mul i64 %e1, %e1
+  %f3 = sext i64 %f1 to i128
   %f4 = mul i128 %e2, %f3
   %f6 = add i128 %e3, %f4
   %f7 = xor i128 %e4, %f6
   %f8 = xor i128 %e5, %f7
   %a1 = ashr i128 %f8, %e5
-  %f5 = trunc i128 %a1 to i32
+  %f5 = trunc i128 %a1 to i64
   br label %if.endif
 
 if.endif:
-  %r1 = phi i32 [ %val, %if.true ], [ %f1, %if.false ]
-  %r2 = phi i32 [ %val, %if.true ], [ %f5, %if.false ]
-  %res = add i32 %r1, %r2
-  ret i32 %res
+  %r1 = phi i64 [ %val, %if.true ], [ %f1, %if.false ]
+  %r2 = phi i64 [ %val, %if.true ], [ %f5, %if.false ]
+  %res = add i64 %r1, %r2
+  ret i64 %res
 }